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# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
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# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
# coding: utf-8
# pylint: disable=too-many-lines, protected-access
# pylint: disable=import-error, no-name-in-module, undefined-variable
"""NDArray API of MXNet."""
from __future__ import absolute_import
from __future__ import division
try:
from __builtin__ import slice as py_slice
except ImportError:
from builtins import slice as py_slice
from array import array as native_array
import ctypes
import warnings
import operator
from functools import reduce # pylint: disable=redefined-builtin
import numpy as np
from ..base import _LIB, numeric_types, integer_types
from ..base import c_str, c_array, c_array_buf, c_handle_array, mx_real_t
from ..base import mx_uint, NDArrayHandle, check_call, DLPackHandle
from ..base import ctypes2buffer
from ..context import Context, current_context
from . import _internal
from . import op
from ._internal import NDArrayBase
__all__ = ["NDArray", "concatenate", "_DTYPE_NP_TO_MX", "_DTYPE_MX_TO_NP", "_GRAD_REQ_MAP",
"ones", "add", "arange", "eye", "divide", "equal", "full", "greater", "greater_equal",
"imdecode", "lesser", "lesser_equal", "logical_and", "logical_or", "logical_xor",
"maximum", "minimum", "moveaxis", "modulo", "multiply", "not_equal", "onehot_encode",
"power", "subtract", "true_divide", "waitall", "_new_empty_handle", "histogram",
"to_dlpack_for_read", "to_dlpack_for_write", "from_dlpack"]
_STORAGE_TYPE_UNDEFINED = -1
_STORAGE_TYPE_DEFAULT = 0
_STORAGE_TYPE_ROW_SPARSE = 1
_STORAGE_TYPE_CSR = 2
# pylint: disable= no-member
_DTYPE_NP_TO_MX = {
None: -1,
np.float32: 0,
np.float64: 1,
np.float16: 2,
np.uint8: 3,
np.int32: 4,
np.int8: 5,
np.int64: 6,
}
_DTYPE_MX_TO_NP = {
-1: None,
0: np.float32,
1: np.float64,
2: np.float16,
3: np.uint8,
4: np.int32,
5: np.int8,
6: np.int64,
}
_STORAGE_TYPE_STR_TO_ID = {
'undefined': _STORAGE_TYPE_UNDEFINED,
'default': _STORAGE_TYPE_DEFAULT,
'row_sparse': _STORAGE_TYPE_ROW_SPARSE,
'csr': _STORAGE_TYPE_CSR,
}
_STORAGE_TYPE_ID_TO_STR = {
_STORAGE_TYPE_UNDEFINED: 'undefined',
_STORAGE_TYPE_DEFAULT: 'default',
_STORAGE_TYPE_ROW_SPARSE: 'row_sparse',
_STORAGE_TYPE_CSR: 'csr',
}
_GRAD_REQ_MAP = {
'null': 0,
'write': 1,
'add': 3
}
# pylint: enable= no-member
# Return code for dispatching indexing function call
_NDARRAY_UNSUPPORTED_INDEXING = -1
_NDARRAY_BASIC_INDEXING = 0
_NDARRAY_ADVANCED_INDEXING = 1
def _new_empty_handle():
"""Returns a new empty handle.
Empty handle can be used to hold a result.
Returns
-------
handle
A new empty `NDArray` handle.
"""
hdl = NDArrayHandle()
check_call(_LIB.MXNDArrayCreateNone(ctypes.byref(hdl)))
return hdl
def _new_alloc_handle(shape, ctx, delay_alloc, dtype=mx_real_t):
"""Return a new handle with specified shape and context.
Empty handle is only used to hold results.
Returns
-------
handle
A new empty `NDArray` handle.
"""
hdl = NDArrayHandle()
check_call(_LIB.MXNDArrayCreateEx(
c_array_buf(mx_uint, native_array('I', shape)),
mx_uint(len(shape)),
ctypes.c_int(ctx.device_typeid),
ctypes.c_int(ctx.device_id),
ctypes.c_int(int(delay_alloc)),
ctypes.c_int(int(_DTYPE_NP_TO_MX[np.dtype(dtype).type])),
ctypes.byref(hdl)))
return hdl
def _new_from_shared_mem(shared_pid, shared_id, shape, dtype):
hdl = NDArrayHandle()
check_call(_LIB.MXNDArrayCreateFromSharedMem(
ctypes.c_int(shared_pid),
ctypes.c_int(shared_id),
c_array(mx_uint, shape),
mx_uint(len(shape)),
ctypes.c_int(int(_DTYPE_NP_TO_MX[np.dtype(dtype).type])),
ctypes.byref(hdl)))
return hdl
[docs]def waitall():
"""Wait for all async operations to finish in MXNet.
This function is used for benchmarking only.
"""
check_call(_LIB.MXNDArrayWaitAll())
def _storage_type(handle):
storage_type = ctypes.c_int(0)
check_call(_LIB.MXNDArrayGetStorageType(handle, ctypes.byref(storage_type)))
return storage_type.value
[docs]class NDArray(NDArrayBase):
"""An array object representing a multidimensional, homogeneous array of
fixed-size items.
"""
__slots__ = []
# make numpy functions return NDArray instead of numpy object array
__array_priority__ = 1000.0
# Extension type code for TVM function.
# See C++ side of definition(kTVMNDArrayTypeCode) at include/mxmet/tensor_blob.h
_tvm_tcode = 19
# pylint: disable= no-member, undefined-variable
@property
def _tvm_handle(self):
return self.handle.value
[docs] def __repr__(self):
"""Returns a string representation of the array."""
shape_info = 'x'.join(['%d' % x for x in self.shape])
return '\n%s\n<%s %s @%s>' % (str(self.asnumpy()),
self.__class__.__name__,
shape_info, self.context)
def __reduce__(self):
return NDArray, (None,), self.__getstate__()
def _to_shared_mem(self):
shared_pid = ctypes.c_int()
shared_id = ctypes.c_int()
check_call(_LIB.MXNDArrayGetSharedMemHandle(
self.handle, ctypes.byref(shared_pid), ctypes.byref(shared_id)))
return shared_pid.value, shared_id.value, self.shape, self.dtype
[docs] def __add__(self, other):
"""x.__add__(y) <=> x+y <=> mx.nd.add(x, y) """
return add(self, other)
[docs] def __iadd__(self, other):
"""x.__iadd__(y) <=> x+=y """
if not self.writable:
raise ValueError('trying to add to a readonly NDArray')
if isinstance(other, NDArray):
return op.broadcast_add(self, other, out=self)
elif isinstance(other, numeric_types):
return _internal._plus_scalar(self, float(other), out=self)
else:
raise TypeError('type %s not supported' % str(type(other)))
def __radd__(self, other):
return self.__add__(other)
[docs] def __sub__(self, other):
"""x.__sub__(y) <=> x-y <=> mx.nd.subtract(x, y) """
return subtract(self, other)
[docs] def __isub__(self, other):
"""x.__isub__(y) <=> x-=y """
if not self.writable:
raise ValueError('trying to subtract from a readonly NDArray')
if isinstance(other, NDArray):
return op.broadcast_sub(self, other, out=self)
elif isinstance(other, numeric_types):
return _internal._minus_scalar(self, float(other), out=self)
else:
raise TypeError('type %s not supported' % str(type(other)))
[docs] def __rsub__(self, other):
"""x.__rsub__(y) <=> y-x <=> mx.nd.subtract(y, x) """
return subtract(other, self)
[docs] def __mul__(self, other):
"""x.__mul__(y) <=> x*y <=> mx.nd.multiply(x, y) """
return multiply(self, other)
[docs] def __neg__(self):
"""x.__neg__(y) <=> -x """
return _internal._mul_scalar(self, -1.0)
[docs] def __imul__(self, other):
"""x.__imul__(y) <=> x*=y """
if not self.writable:
raise ValueError('trying to multiply to a readonly NDArray')
if isinstance(other, NDArray):
return op.broadcast_mul(self, other, out=self)
elif isinstance(other, numeric_types):
return _internal._mul_scalar(self, float(other), out=self)
else:
raise TypeError('type %s not supported' % str(type(other)))
def __rmul__(self, other):
return self.__mul__(other)
[docs] def __div__(self, other):
"""x.__div__(y) <=> x/y <=> mx.nd.divide(x, y) """
return divide(self, other)
[docs] def __rdiv__(self, other):
"""x.__rdiv__(y) <=> y/x <=> mx.nd.divide(y, x) """
return divide(other, self)
[docs] def __idiv__(self, other):
"""x.__rdiv__(y) <=> x/=y """
if not self.writable:
raise ValueError('trying to divide from a readonly NDArray')
if isinstance(other, NDArray):
return op.broadcast_div(self, other, out=self)
elif isinstance(other, numeric_types):
return _internal._div_scalar(self, float(other), out=self)
else:
raise TypeError('type %s not supported' % str(type(other)))
def __truediv__(self, other):
return divide(self, other)
def __rtruediv__(self, other):
return divide(other, self)
def __itruediv__(self, other):
return self.__idiv__(other)
[docs] def __mod__(self, other):
"""x.__mod__(y) <=> x%y <=> mx.nd.modulo(x, y) """
return modulo(self, other)
[docs] def __rmod__(self, other):
"""x.__rmod__(y) <=> y%x <=> mx.nd.modulo(y, x) """
return modulo(other, self)
[docs] def __imod__(self, other):
"""x.__rmod__(y) <=> x%=y """
if not self.writable:
raise ValueError('trying to take modulo from a readonly NDArray')
if isinstance(other, NDArray):
return op.broadcast_mod(self, other, out=self)
elif isinstance(other, numeric_types):
return _internal._mod_scalar(self, float(other), out=self)
else:
raise TypeError('type %s not supported' % str(type(other)))
[docs] def __pow__(self, other):
"""x.__pow__(y) <=> x**y <=> mx.nd.power(x,y) """
return power(self, other)
[docs] def __rpow__(self, other):
"""x.__pow__(y) <=> y**x <=> mx.nd.power(y,x) """
return power(other, self)
[docs] def __eq__(self, other):
"""x.__eq__(y) <=> x==y <=> mx.nd.equal(x, y) """
return equal(self, other)
[docs] def __hash__(self):
"""Default hash function."""
return id(self)//16
[docs] def __ne__(self, other):
"""x.__ne__(y) <=> x!=y <=> mx.nd.not_equal(x, y) """
return not_equal(self, other)
[docs] def __gt__(self, other):
"""x.__gt__(y) <=> x>y <=> mx.nd.greater(x, y) """
return greater(self, other)
[docs] def __ge__(self, other):
"""x.__ge__(y) <=> x>=y <=> mx.nd.greater_equal(x, y) """
return greater_equal(self, other)
[docs] def __lt__(self, other):
"""x.__lt__(y) <=> x mx.nd.lesser(x, y) """
return lesser(self, other)
[docs] def __le__(self, other):
"""x.__le__(y) <=> x<=y <=> mx.nd.less_equal(x, y) """
return lesser_equal(self, other)
def __bool__(self):
num_elements = reduce(operator.mul, self.shape, 1)
if num_elements == 0:
return False
elif num_elements == 1:
return bool(self.asscalar())
else:
raise ValueError("The truth value of an NDArray with multiple elements " \
"is ambiguous.")
__nonzero__ = __bool__
[docs] def __len__(self):
"""Number of element along the first axis."""
return self.shape[0]
def __getstate__(self):
handle = self.handle
this = {'handle' : None}
if handle is not None:
length = ctypes.c_size_t()
cptr = ctypes.POINTER(ctypes.c_char)()
check_call(_LIB.MXNDArraySaveRawBytes(self.handle,
ctypes.byref(length),
ctypes.byref(cptr)))
this['handle'] = ctypes2buffer(cptr, length.value)
return this
def __setstate__(self, state):
# pylint: disable=assigning-non-slot
handle = state['handle']
if handle is not None:
buf = handle
handle = NDArrayHandle()
ptr = (ctypes.c_char * len(buf)).from_buffer(buf)
length = ctypes.c_size_t(len(buf))
check_call(_LIB.MXNDArrayLoadFromRawBytes(ptr, length, ctypes.byref(handle)))
self.handle = handle
else:
self.handle = None
# pylint: disable=line-too-long
[docs] def __setitem__(self, key, value):
"""x.__setitem__(i, y) <=> x[i]=y
Sets value to self[key]. This functions supports advanced indexing defined in the following reference with
some restrictions.
https://docs.scipy.org/doc/numpy-1.13.0/reference/arrays.indexing.html#combining-advanced-and-basic-indexing
- If key is a list type, only a list of integers is supported, e.g. key=[1, 2] is supported,
while not for key=[[1, 2]].
- Ellipsis (...) and np.newaxis are not supported.
- Boolean array indexing is not supported.
Parameters
----------
key : int, mxnet.ndarray.slice, list, np.ndarray, NDArray, or tuple of all previous types
The indexing key.
value : scalar or array-like object that can be broadcast to the shape of self[key]
The value to set.
Examples
--------
>>> x = mx.nd.zeros((2,3))
>>> x[:] = 1
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> x[:,1:2] = 2
>>> x.asnumpy()
array([[ 1., 2., 1.],
[ 1., 2., 1.]], dtype=float32)
>>> x[1:2,1:] = 3
>>> x.asnumpy()
array([[ 1., 2., 1.],
[ 1., 3., 3.]], dtype=float32)
>>> x[1:,0:2] = mx.nd.zeros((1,2))
>>> x.asnumpy()
array([[ 1., 2., 1.],
[ 0., 0., 3.]], dtype=float32)
>>> x[1,2] = 4
>>> x.asnumpy()
array([[ 1., 2., 1.],
[ 0., 0., 4.]], dtype=float32)
>>> x[[0], [1, 2]] = 5
>>> x.asnumpy()
array([[ 1., 5., 5.],
[ 0., 0., 4.]], dtype=float32)
>>> x[::-1, 0:2:2] = [6]
>>> x.asnumpy()
array([[ 6., 5., 5.],
[ 6., 0., 4.]], dtype=float32)
"""
indexing_dispatch_code = _get_indexing_dispatch_code(key)
if indexing_dispatch_code == _NDARRAY_BASIC_INDEXING:
self._set_nd_basic_indexing(key, value)
elif indexing_dispatch_code == _NDARRAY_ADVANCED_INDEXING:
self._set_nd_advanced_indexing(key, value)
else:
raise ValueError('Indexing NDArray with index=%s and type=%s is not supported'
% (str(key), str(type(key))))
# pylint: enable=line-too-long
# pylint: disable=line-too-long
[docs] def __getitem__(self, key):
"""x.__getitem__(i) <=> x[i]
Returns a sliced view of this array if the elements fetched are contiguous in memory;
otherwise, returns a newly created NDArray.
This functions supports advanced indexing defined in the following reference with
some restrictions.
https://docs.scipy.org/doc/numpy-1.13.0/reference/arrays.indexing.html#combining-advanced-and-basic-indexing
- If key is a list type, only a list of integers is supported, e.g. key=[1, 2] is supported,
while not for key=[[1, 2]].
- Ellipsis (...) and np.newaxis are not supported.
- Boolean array indexing is not supported.
Parameters
----------
key : int, mxnet.ndarray.slice, list, np.ndarray, NDArray, or tuple of all previous types
Indexing key.
Examples
--------
>>> x = mx.nd.arange(0,6).reshape((2,3))
>>> x.asnumpy()
array([[ 0., 1., 2.],
[ 3., 4., 5.]], dtype=float32)
>>> x[1].asnumpy()
array([ 3., 4., 5.], dtype=float32)
>>> y = x[0:1]
>>> y[:] = 2
>>> x.asnumpy()
array([[ 2., 2., 2.],
[ 3., 4., 5.]], dtype=float32)
>>> x = mx.nd.arange(0, 8, dtype='int32').reshape((2, 2, 2))
>>> x[[0, 1]]
[[[0 1]
[2 3]]
[[4 5]
[6 7]]]
>>> x[1:, [0, 1]]
[[[4 5]
[6 7]]]
>>> y = np.array([0, 1], dtype='int32')
>>> x[1:, y]
[[[4 5]
[6 7]]]
>>> y = mx.nd.array([0, 1], dtype='int32')
>>> x[1:, y]
[[[4 5]
[6 7]]]
"""
indexing_dispatch_code = _get_indexing_dispatch_code(key)
if indexing_dispatch_code == _NDARRAY_BASIC_INDEXING:
return self._get_nd_basic_indexing(key)
elif indexing_dispatch_code == _NDARRAY_ADVANCED_INDEXING:
return self._get_nd_advanced_indexing(key)
else:
raise ValueError('Indexing NDArray with index=%s and type=%s is not supported'
% (str(key), str(type(key))))
# pylint: enable=line-too-long
def _get_index_nd(self, key):
"""Returns an index array for use in scatter_nd and gather_nd."""
def _is_advanced_index(index):
"""The definition of advanced index here includes integers as well, while
integers are considered as basic index type when the key contains only
slices and integers."""
return not isinstance(index, py_slice)
if isinstance(key, (NDArray, np.ndarray, list, integer_types, py_slice)):
key = (key,)
assert isinstance(key, tuple),\
'index=%s must be a NDArray, or np.ndarray, or list, or tuple ' \
' type to use advanced indexing, received type=%s' % (str(key), str(type(key)))
assert len(key) > 0, "Cannot slice with empty indices"
shape = self.shape
assert len(shape) >= len(key),\
"Slicing dimensions exceeds array dimensions, %d vs %d" % (len(key), len(shape))
indices = []
dtype = 'int32' # index data type passed to gather_nd op
need_broadcast = (len(key) != 1)
advanced_indices = [] # include list, NDArray, np.ndarray, integer
basic_indices = [] # include only slices
advanced_index_bshape = None # final advanced index shape
for i, idx_i in enumerate(key):
is_advanced_index = True
if isinstance(idx_i, (np.ndarray, list, tuple)):
idx_i = array(idx_i, ctx=self.context, dtype=dtype)
advanced_indices.append(i)
elif isinstance(idx_i, py_slice):
start, stop, step = _get_index_range(idx_i.start, idx_i.stop, shape[i], idx_i.step)
idx_i = arange(start, stop, step, ctx=self.context, dtype=dtype)
basic_indices.append(i)
is_advanced_index = False
elif isinstance(idx_i, integer_types):
start, stop, step = _get_index_range(idx_i, idx_i+1, shape[i], 1)
idx_i = arange(start, stop, step, ctx=self.context, dtype=dtype)
advanced_indices.append(i)
elif isinstance(idx_i, NDArray):
if dtype != idx_i.dtype:
idx_i = idx_i.astype(dtype)
advanced_indices.append(i)
else:
raise IndexError('Indexing NDArray with index=%s of type=%s is not supported'
% (str(key), str(type(key))))
if is_advanced_index:
if advanced_index_bshape is None:
advanced_index_bshape = idx_i.shape
elif advanced_index_bshape != idx_i.shape:
need_broadcast = True
advanced_index_bshape = _get_broadcast_shape(advanced_index_bshape, idx_i.shape)
indices.append(idx_i)
# Get final index shape for gather_nd. See the following reference
# for determining the output array shape.
# https://docs.scipy.org/doc/numpy-1.13.0/reference/arrays.indexing.html#combining-advanced-and-basic-indexing # pylint: disable=line-too-long
if len(advanced_indices) == 0:
raise ValueError('Advanced index tuple must contain at least one of the following types:'
' list, tuple, NDArray, np.ndarray, integer, received index=%s' % key)
# determine the output array's shape by checking whether advanced_indices are all adjacent
# or separated by slices
advanced_indices_adjacent = True
for i in range(0, len(advanced_indices)-1):
if advanced_indices[i] + 1 != advanced_indices[i+1]:
advanced_indices_adjacent = False
break
index_bshape_list = [] # index broadcasted shape
if advanced_indices_adjacent:
for i in range(0, advanced_indices[0]):
index_bshape_list.extend(indices[i].shape)
if not need_broadcast and indices[i].shape != advanced_index_bshape:
need_broadcast = True
index_bshape_list.extend(advanced_index_bshape)
for i in range(advanced_indices[-1]+1, len(indices)):
if not need_broadcast and indices[i].shape != advanced_index_bshape:
need_broadcast = True
index_bshape_list.extend(indices[i].shape)
else:
index_bshape_list.extend(advanced_index_bshape)
for i in basic_indices:
index_bshape_list.extend(indices[i].shape)
if not need_broadcast and indices[i].shape != advanced_index_bshape:
need_broadcast = True
index_bshape = tuple(index_bshape_list)
# Need to broadcast all ndarrays in indices to the final shape.
# For example, suppose an array has shape=(5, 6, 7, 8) and
# key=(slice(1, 5), [[1, 2]], slice(2, 5), [1]).
# Since key[1] and key[3] are two advanced indices here and they are
# separated by basic indices key[0] and key[2], the output shape
# is (1, 2, 4, 3), where the first two elements come from the shape
# that key[1] and key[3] should broadcast to, which is (1, 2), and
# the last two elements come from the shape of two basic indices.
# In order to broadcast all basic and advanced indices to the output shape,
# we need to reshape them based on their axis. For example, to broadcast key[0],
# with shape=(4,), we first need to reshape it into (1, 1, 4, 1), and then
# broadcast the reshaped array to (1, 2, 4, 3); to broadcast key[1], we first
# reshape it into (1, 2, 1, 1), then broadcast the reshaped array to (1, 2, 4, 3).
if need_broadcast:
broadcasted_indices = []
idx_rshape = [1] * len(index_bshape)
if advanced_indices_adjacent:
advanced_index_bshape_start = advanced_indices[0] # start index of advanced_index_bshape in index_shape
advanced_index_bshape_stop = advanced_index_bshape_start + len(advanced_index_bshape)
for i, idx in enumerate(key):
if _is_advanced_index(idx):
k = advanced_index_bshape_stop
# find the reshaped shape for indices[i]
for dim_size in indices[i].shape[::-1]:
k -= 1
idx_rshape[k] = dim_size
else:
if i < advanced_indices[0]: # slice is on the left side of advanced indices
idx_rshape[i] = indices[i].shape[0]
elif i > advanced_indices[-1]: # slice is on the right side of advanced indices
idx_rshape[i-len(key)] = indices[i].shape[0]
else:
raise ValueError('basic index i=%d cannot be between advanced index i=%d and i=%d'
% (i, advanced_indices[0], advanced_indices[-1]))
# broadcast current index to the final shape
broadcasted_indices.append(indices[i].reshape(tuple(idx_rshape)).broadcast_to(index_bshape))
# reset idx_rshape to ones
for j, _ in enumerate(idx_rshape):
idx_rshape[j] = 1
else:
basic_index_offset = len(advanced_index_bshape)
for i, idx in enumerate(key):
if _is_advanced_index(idx):
k = len(advanced_index_bshape)
for dim_size in indices[i].shape[::-1]:
k -= 1
idx_rshape[k] = dim_size
else:
idx_rshape[basic_index_offset] = indices[i].shape[0]
basic_index_offset += 1
# broadcast current index to the final shape
broadcasted_indices.append(indices[i].reshape(tuple(idx_rshape)).broadcast_to(index_bshape))
# reset idx_rshape to ones
for j, _ in enumerate(idx_rshape):
idx_rshape[j] = 1
indices = broadcasted_indices
return op.stack(*indices)
def _prepare_value_nd(self, value, vshape):
"""Given value and vshape, create an `NDArray` from value with the same
context and dtype as the current one and broadcast it to vshape."""
if isinstance(value, numeric_types):
value_nd = full(shape=vshape, val=value, ctx=self.context, dtype=self.dtype)
elif isinstance(value, NDArray):
value_nd = value.as_in_context(self.context)
if value_nd.dtype != self.dtype:
value_nd = value_nd.astype(self.dtype)
else:
try:
value_nd = array(value, ctx=self.context, dtype=self.dtype)
except:
raise TypeError('NDArray does not support assignment with non-array-like'
' object %s of type %s' % (str(value), str(type(value))))
if value_nd.shape != vshape:
value_nd = value_nd.broadcast_to(vshape)
return value_nd
def _set_nd_basic_indexing(self, key, value):
"""This function is called by __setitem__ when key is a basic index, i.e.
an integer, or a slice, or a tuple of integers and slices. No restrictions
on the values of slices' steps."""
shape = self.shape
if isinstance(key, integer_types):
if key < 0:
key += shape[0]
if key < 0 or key >= shape[0]:
if key < 0:
key -= shape[0]
raise IndexError('index %d is out of bounds for axis 0 with size %d'
% (key, shape[0]))
key = py_slice(key, key+1) # key must be >= 0 here
if isinstance(key, py_slice):
assign_to_self = key.step is None or key.step == 1
assign_to_self &= key.start is None or key.start == 0
assign_to_self &= key.stop is None or key.stop == shape[0]
if assign_to_self: # trivial case, assign value to self
if isinstance(value, NDArray):
if value.handle is not self.handle:
if value.shape != shape:
value = value.broadcast_to(shape)
value.copyto(self)
elif isinstance(value, numeric_types):
_internal._full(shape=shape, ctx=self.context,
dtype=self.dtype, value=float(value), out=self)
elif isinstance(value, (np.ndarray, np.generic)):
if isinstance(value, np.generic) or value.shape != shape:
value = np.broadcast_to(value, shape)
self._sync_copyfrom(value)
else: # value might be a list or a tuple
value_nd = self._prepare_value_nd(value, shape)
value_nd.copyto(self)
return
else: # non-trivial case, use _slice_assign or _slice_assign_scalar
key = (key,)
assert isinstance(key, tuple), "key=%s must be a tuple of slices and integers" % str(key)
assert len(key) <= len(shape), "Indexing dimensions exceed array dimensions, %d vs %d"\
% (len(key), len(shape))
begin = []
end = []
steps = []
oshape = [] # output shape of slice using key
vshape = [] # value shape of data[key]
for i, slice_i in enumerate(key):
dim_size = 1
if isinstance(slice_i, py_slice):
begin.append(slice_i.start)
end.append(slice_i.stop)
steps.append(slice_i.step)
start, stop, step = _get_index_range(slice_i.start, slice_i.stop,
shape[i], slice_i.step)
dim_size = _get_dim_size(start, stop, step)
vshape.append(dim_size)
elif isinstance(slice_i, integer_types):
begin.append(slice_i)
end.append(slice_i+1 if slice_i != -1 else self.shape[i])
steps.append(1)
else:
raise ValueError("basic indexing does not support index=%s of type=%s"
% (str(slice_i), str(type(slice_i))))
oshape.append(dim_size)
oshape.extend(shape[len(key):])
vshape.extend(shape[len(key):])
# if key contains all integers, vshape should be (1,)
if len(vshape) == 0:
vshape.append(1)
oshape = tuple(oshape)
vshape = tuple(vshape)
if isinstance(value, numeric_types):
_internal._slice_assign_scalar(self, out=self, begin=begin, end=end,
step=steps, scalar=float(value))
else:
value_nd = self._prepare_value_nd(value, vshape)
if vshape != oshape:
value_nd = value_nd.reshape(oshape)
_internal._slice_assign(self, value_nd, begin, end, steps, out=self)
def _set_nd_advanced_indexing(self, key, value):
"""This function is called by __setitem__ when key is an advanced index."""
indices = self._get_index_nd(key)
vshape = _get_oshape_of_gather_nd_op(self.shape, indices.shape)
value_nd = self._prepare_value_nd(value, vshape)
_internal._scatter_set_nd(lhs=self, rhs=value_nd, indices=indices,
shape=self.shape, out=self)
def _get_nd_basic_indexing(self, key):
"""This function is called when key is a slice, or an integer,
or a tuple of slices or integers"""
shape = self.shape
if isinstance(key, integer_types):
if key > shape[0] - 1:
raise IndexError(
'index {} is out of bounds for axis 0 with size {}'.format(
key, shape[0]))
return self._at(key)
elif isinstance(key, py_slice):
if key.step is not None and key.step != 1:
if key.step == 0:
raise ValueError("slice step cannot be zero")
return op.slice(self, begin=(key.start,), end=(key.stop,), step=(key.step,))
elif key.start is not None or key.stop is not None:
return self._slice(key.start, key.stop)
else:
return self
if not isinstance(key, tuple):
raise ValueError('index=%s must be a slice, or an ineger, or a tuple'
' of slices and integers to use basic indexing, received type=%s'
% (str(key), str(type(key))))
assert len(key) != 0, 'basic index cannot be an empty tuple'
begin = []
end = []
step = []
kept_axes = [] # axes where slice_i is a slice
i = -1
for i, slice_i in enumerate(key):
if isinstance(slice_i, integer_types):
begin.append(slice_i)
end.append(slice_i+1 if slice_i != -1 else self.shape[i])
step.append(1)
elif isinstance(slice_i, py_slice):
if slice_i.step == 0:
raise ValueError('basic index=%s cannot have slice=%s with step = 0'
% (str(key), str(slice_i)))
begin.append(slice_i.start)
end.append(slice_i.stop)
step.append(slice_i.step)
kept_axes.append(i)
else:
raise ValueError('basic_indexing does not support slicing with '
'index=%s of type=%s.' % (str(slice_i), str(type(slice_i))))
kept_axes.extend(range(i+1, len(shape)))
sliced_nd = op.slice(self, begin, end, step)
if len(kept_axes) == len(shape):
return sliced_nd
# squeeze sliced_shape to remove the axes indexed by integers
oshape = []
sliced_shape = sliced_nd.shape
for axis in kept_axes:
oshape.append(sliced_shape[axis])
# if key is a tuple of integers, still need to keep 1 dim
# while in Numpy, the output will become an value instead of an ndarray
if len(oshape) == 0:
oshape.append(1)
oshape = tuple(oshape)
assert np.prod(oshape) == np.prod(sliced_shape), 'oshape=%s has different size'\
' than sliced_shape=%s'\
% (oshape, sliced_shape)
return sliced_nd.reshape(oshape)
def _get_nd_advanced_indexing(self, key):
"""Get item when key is a tuple of any objects of the following types:
NDArray, np.ndarray, list, tuple, slice, and integer."""
return op.gather_nd(self, self._get_index_nd(key))
def _sync_copyfrom(self, source_array):
"""Performs a synchronized copy from the `source_array` to the current array.
This is called through ``x[:] = source_array``, where the `source_array`
is a `numpy.ndarray` or array-like object.
This function blocks until all the pending read/write operations with respect
to the current `NDArray` are finished and carry out the copy operation to the
current NDArray.
Parameters
----------
source_array : array_like
The data source we would like to copy from.
Example
-------
>>> a = mx.nd.array([1, 2])
>>> a.asnumpy()
array([ 1., 2.], dtype=float32)
>>> a[:] = np.array([3, 4])
>> a.asnumpy()
array([ 3., 4.], dtype=float32)
"""
if not isinstance(source_array, np.ndarray):
try:
source_array = np.array(source_array, dtype=self.dtype)
except:
raise TypeError('array must consist of array-like data,' +
'type %s is not supported' % str(type(array)))
source_array = np.asarray(source_array, dtype=self.dtype, order='C')
if source_array.shape != self.shape:
raise ValueError('Shape inconsistent: expected %s vs got %s'%(
str(source_array.shape), str(self.shape)))
check_call(_LIB.MXNDArraySyncCopyFromCPU(
self.handle,
source_array.ctypes.data_as(ctypes.c_void_p),
ctypes.c_size_t(source_array.size)))
def _slice(self, start, stop):
"""Returns a sliced NDArray that shares memory with the current one.
This is called through ``x[start:stop]``.
Parameters
----------
start : int
Starting inclusive index of slice in the first dim.
stop : int
Finishing exclusive index of slice in the first dim.
Returns
-------
`NDArray` sharing the memory with the current one sliced from
start to stop in the first dim.
Examples:
>>> a = mx.nd.array([[1,2], [3, 4], [5, 6], [7, 8]])
>>> a[1:2].asnumpy()
array([[ 3., 4.]], dtype=float32)
>>> a[1:1].asnumpy()
array([], shape=(0, 2), dtype=float32)
"""
handle = NDArrayHandle()
start, stop, _ = _get_index_range(start, stop, self.shape[0])
check_call(_LIB.MXNDArraySlice(
self.handle, mx_uint(start), mx_uint(stop), ctypes.byref(handle)))
return NDArray(handle=handle, writable=self.writable)
def _at(self, idx):
"""Returns a view of the array sliced at `idx` in the first dim.
This is called through ``x[idx]``.
Parameters
----------
idx : int
index for slicing the `NDArray` in the first dim.
Returns
-------
NDArray
`NDArray` sharing the memory with the current one sliced at `idx` in the first dim.
Examples
--------
>>> a = mx.nd.array([[1,2], [3, 4]])
>>> a[1].asnumpy()
array([ 3., 4.], dtype=float32)
>>> b = mx.nd.array([1, 2, 3, 4])
>>> b[0].asnumpy()
array([ 1.], dtype=float32)
"""
handle = NDArrayHandle()
if idx < 0:
length = self.shape[0]
idx += length
if idx < 0:
raise IndexError('index %d is out of bounds for axis 0 with size %d'
% (idx-length, length))
check_call(_LIB.MXNDArrayAt(
self.handle, mx_uint(idx), ctypes.byref(handle)))
return NDArray(handle=handle, writable=self.writable)
[docs] def reshape(self, *shape, **kwargs):
"""Returns a **view** of this array with a new shape without altering any data.
Parameters
----------
shape : tuple of int, or n ints
The new shape should not change the array size, namely
``np.prod(new_shape)`` should be equal to ``np.prod(self.shape)``.
Some dimensions of the shape can take special values from the set {0, -1, -2, -3, -4}.
The significance of each is explained below:
- ``0`` copy this dimension from the input to the output shape.
Example::
- input shape = (2,3,4), shape = (4,0,2), output shape = (4,3,2)
- input shape = (2,3,4), shape = (2,0,0), output shape = (2,3,4)
- ``-1`` infers the dimension of the output shape by using the remainder of the
input dimensions keeping the size of the new array same as that of the input array.
At most one dimension of shape can be -1.
Example::
- input shape = (2,3,4), shape = (6,1,-1), output shape = (6,1,4)
- input shape = (2,3,4), shape = (3,-1,8), output shape = (3,1,8)
- input shape = (2,3,4), shape=(-1,), output shape = (24,)
- ``-2`` copy all/remainder of the input dimensions to the output shape.
Example::
- input shape = (2,3,4), shape = (-2,), output shape = (2,3,4)
- input shape = (2,3,4), shape = (2,-2), output shape = (2,3,4)
- input shape = (2,3,4), shape = (-2,1,1), output shape = (2,3,4,1,1)
- ``-3`` use the product of two consecutive dimensions of the input shape as the
output dimension.
Example::
- input shape = (2,3,4), shape = (-3,4), output shape = (6,4)
- input shape = (2,3,4,5), shape = (-3,-3), output shape = (6,20)
- input shape = (2,3,4), shape = (0,-3), output shape = (2,12)
- input shape = (2,3,4), shape = (-3,-2), output shape = (6,4)
- ``-4`` split one dimension of the input into two dimensions passed subsequent to
-4 in shape (can contain -1).
Example::
- input shape = (2,3,4), shape = (-4,1,2,-2), output shape =(1,2,3,4)
- input shape = (2,3,4), shape = (2,-4,-1,3,-2), output shape = (2,1,3,4)
- If the argument `reverse` is set to 1, then the special values are inferred from right
to left.
Example::
- without reverse=1, for input shape = (10,5,4), shape = (-1,0), output shape would be \
(40,5).
- with reverse=1, output shape will be (50,4).
reverse : bool, default False
If true then the special values are inferred from right to left. Only supported as
keyword argument.
Returns
-------
NDArray
An array with desired shape that shares data with this array.
Examples
--------
>>> x = mx.nd.arange(0,6).reshape(2,3)
>>> x.asnumpy()
array([[ 0., 1., 2.],
[ 3., 4., 5.]], dtype=float32)
>>> y = x.reshape(3,2)
>>> y.asnumpy()
array([[ 0., 1.],
[ 2., 3.],
[ 4., 5.]], dtype=float32)
>>> y = x.reshape(3,-1)
>>> y.asnumpy()
array([[ 0., 1.],
[ 2., 3.],
[ 4., 5.]], dtype=float32)
>>> y = x.reshape(3,2)
>>> y.asnumpy()
array([[ 0., 1.],
[ 2., 3.],
[ 4., 5.]], dtype=float32)
>>> y = x.reshape(-3)
>>> y.asnumpy()
array([ 0. 1. 2. 3. 4. 5.], dtype=float32)
>>> y[:] = -1
>>> x.asnumpy()
array([[-1., -1., -1.],
[-1., -1., -1.]], dtype=float32)
"""
if len(shape) == 1 and isinstance(shape[0], (list, tuple)):
shape = shape[0]
elif not shape:
shape = kwargs.get('shape')
assert shape, "Shape must be provided."
if not all(k in ['shape', 'reverse'] for k in kwargs):
raise TypeError(
"Got unknown keywords in reshape: {}. " \
"Accepted keyword arguments are 'shape' and 'reverse'.".format(
', '.join([k for k in kwargs if k not in ['shape', 'reverse']])))
reverse = kwargs.get('reverse', False)
handle = NDArrayHandle()
# Actual reshape
check_call(_LIB.MXNDArrayReshape64(self.handle,
len(shape),
c_array(ctypes.c_int64, shape),
reverse,
ctypes.byref(handle)))
return NDArray(handle=handle, writable=self.writable)
[docs] def reshape_like(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`reshape_like`.
The arguments are the same as for :py:func:`reshape_like`, with
this array as data.
"""
return op.reshape_like(self, *args, **kwargs)
[docs] def zeros_like(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`zeros_like`.
The arguments are the same as for :py:func:`zeros_like`, with
this array as data.
"""
return op.zeros_like(self, *args, **kwargs)
[docs] def ones_like(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`ones_like`.
The arguments are the same as for :py:func:`ones_like`, with
this array as data.
"""
return op.ones_like(self, *args, **kwargs)
[docs] def broadcast_axes(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`broadcast_axes`.
The arguments are the same as for :py:func:`broadcast_axes`, with
this array as data.
"""
return op.broadcast_axes(self, *args, **kwargs)
[docs] def repeat(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`repeat`.
The arguments are the same as for :py:func:`repeat`, with
this array as data.
"""
return op.repeat(self, *args, **kwargs)
[docs] def pad(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`pad`.
The arguments are the same as for :py:func:`pad`, with
this array as data.
"""
return op.pad(self, *args, **kwargs)
[docs] def swapaxes(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`swapaxes`.
The arguments are the same as for :py:func:`swapaxes`, with
this array as data.
"""
return op.swapaxes(self, *args, **kwargs)
[docs] def split(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`split`.
The arguments are the same as for :py:func:`split`, with
this array as data.
"""
return op.split(self, *args, **kwargs)
[docs] def slice(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`slice`.
The arguments are the same as for :py:func:`slice`, with
this array as data.
"""
return op.slice(self, *args, **kwargs)
[docs] def slice_axis(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`slice_axis`.
The arguments are the same as for :py:func:`slice_axis`, with
this array as data.
"""
return op.slice_axis(self, *args, **kwargs)
[docs] def slice_like(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`slice_like`.
The arguments are the same as for :py:func:`slice_like`, with
this array as data.
"""
return op.slice_like(self, *args, **kwargs)
[docs] def take(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`take`.
The arguments are the same as for :py:func:`take`, with
this array as data.
"""
return op.take(self, *args, **kwargs)
[docs] def one_hot(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`one_hot`.
The arguments are the same as for :py:func:`one_hot`, with
this array as data.
"""
return op.one_hot(self, *args, **kwargs)
[docs] def pick(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`pick`.
The arguments are the same as for :py:func:`pick`, with
this array as data.
"""
return op.pick(self, *args, **kwargs)
[docs] def sort(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`sort`.
The arguments are the same as for :py:func:`sort`, with
this array as data.
"""
return op.sort(self, *args, **kwargs)
[docs] def topk(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`topk`.
The arguments are the same as for :py:func:`topk`, with
this array as data.
"""
return op.topk(self, *args, **kwargs)
[docs] def argsort(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`argsort`.
The arguments are the same as for :py:func:`argsort`, with
this array as data.
"""
return op.argsort(self, *args, **kwargs)
[docs] def argmax(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`argmax`.
The arguments are the same as for :py:func:`argmax`, with
this array as data.
"""
return op.argmax(self, *args, **kwargs)
[docs] def argmax_channel(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`argmax_channel`.
The arguments are the same as for :py:func:`argmax_channel`, with
this array as data.
"""
return op.argmax_channel(self, *args, **kwargs)
[docs] def argmin(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`argmin`.
The arguments are the same as for :py:func:`argmin`, with
this array as data.
"""
return op.argmin(self, *args, **kwargs)
[docs] def clip(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`clip`.
The arguments are the same as for :py:func:`clip`, with
this array as data.
"""
return op.clip(self, *args, **kwargs)
[docs] def abs(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`abs`.
The arguments are the same as for :py:func:`abs`, with
this array as data.
"""
return op.abs(self, *args, **kwargs)
[docs] def sign(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`sign`.
The arguments are the same as for :py:func:`sign`, with
this array as data.
"""
return op.sign(self, *args, **kwargs)
[docs] def flatten(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`flatten`.
The arguments are the same as for :py:func:`flatten`, with
this array as data.
"""
return op.flatten(self, *args, **kwargs)
[docs] def shape_array(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`shape_array`.
The arguments are the same as for :py:func:`shape_array`, with
this array as data.
"""
return op.shape_array(self, *args, **kwargs)
[docs] def size_array(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`size_array`.
The arguments are the same as for :py:func:`size_array`, with
this array as data.
"""
return op.size_array(self, *args, **kwargs)
[docs] def expand_dims(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`expand_dims`.
The arguments are the same as for :py:func:`expand_dims`, with
this array as data.
"""
return op.expand_dims(self, *args, **kwargs)
[docs] def tile(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`tile`.
The arguments are the same as for :py:func:`tile`, with
this array as data.
"""
return op.tile(self, *args, **kwargs)
[docs] def transpose(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`transpose`.
The arguments are the same as for :py:func:`transpose`, with
this array as data.
"""
return op.transpose(self, *args, **kwargs)
[docs] def flip(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`flip`.
The arguments are the same as for :py:func:`flip`, with
this array as data.
"""
return op.flip(self, *args, **kwargs)
[docs] def depth_to_space(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`depth_to_space`.
The arguments are the same as for :py:func:`depth_to_space`, with
this array as data.
"""
return op.depth_to_space(self, *args, **kwargs)
[docs] def space_to_depth(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`space_to_depth`.
The arguments are the same as for :py:func:`space_to_depth`, with
this array as data.
"""
return op.space_to_depth(self, *args, **kwargs)
[docs] def diag(self, k=0, **kwargs):
"""Convenience fluent method for :py:func:`diag`.
The arguments are the same as for :py:func:`diag`, with
this array as data.
"""
return op.diag(self, k, **kwargs)
[docs] def sum(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`sum`.
The arguments are the same as for :py:func:`sum`, with
this array as data.
"""
return op.sum(self, *args, **kwargs)
[docs] def nansum(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`nansum`.
The arguments are the same as for :py:func:`nansum`, with
this array as data.
"""
return op.nansum(self, *args, **kwargs)
[docs] def prod(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`prod`.
The arguments are the same as for :py:func:`prod`, with
this array as data.
"""
return op.prod(self, *args, **kwargs)
[docs] def nanprod(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`nanprod`.
The arguments are the same as for :py:func:`nanprod`, with
this array as data.
"""
return op.nanprod(self, *args, **kwargs)
[docs] def mean(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`mean`.
The arguments are the same as for :py:func:`mean`, with
this array as data.
"""
return op.mean(self, *args, **kwargs)
[docs] def max(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`max`.
The arguments are the same as for :py:func:`max`, with
this array as data.
"""
return op.max(self, *args, **kwargs)
[docs] def min(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`min`.
The arguments are the same as for :py:func:`min`, with
this array as data.
"""
return op.min(self, *args, **kwargs)
[docs] def norm(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`norm`.
The arguments are the same as for :py:func:`norm`, with
this array as data.
"""
return op.norm(self, *args, **kwargs)
[docs] def round(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`round`.
The arguments are the same as for :py:func:`round`, with
this array as data.
"""
return op.round(self, *args, **kwargs)
[docs] def rint(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`rint`.
The arguments are the same as for :py:func:`rint`, with
this array as data.
"""
return op.rint(self, *args, **kwargs)
[docs] def fix(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`fix`.
The arguments are the same as for :py:func:`fix`, with
this array as data.
"""
return op.fix(self, *args, **kwargs)
[docs] def floor(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`floor`.
The arguments are the same as for :py:func:`floor`, with
this array as data.
"""
return op.floor(self, *args, **kwargs)
[docs] def ceil(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`ceil`.
The arguments are the same as for :py:func:`ceil`, with
this array as data.
"""
return op.ceil(self, *args, **kwargs)
[docs] def trunc(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`trunc`.
The arguments are the same as for :py:func:`trunc`, with
this array as data.
"""
return op.trunc(self, *args, **kwargs)
[docs] def sin(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`sin`.
The arguments are the same as for :py:func:`sin`, with
this array as data.
"""
return op.sin(self, *args, **kwargs)
[docs] def cos(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`cos`.
The arguments are the same as for :py:func:`cos`, with
this array as data.
"""
return op.cos(self, *args, **kwargs)
[docs] def tan(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`tan`.
The arguments are the same as for :py:func:`tan`, with
this array as data.
"""
return op.tan(self, *args, **kwargs)
[docs] def arcsin(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`arcsin`.
The arguments are the same as for :py:func:`arcsin`, with
this array as data.
"""
return op.arcsin(self, *args, **kwargs)
[docs] def arccos(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`arccos`.
The arguments are the same as for :py:func:`arccos`, with
this array as data.
"""
return op.arccos(self, *args, **kwargs)
[docs] def arctan(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`arctan`.
The arguments are the same as for :py:func:`arctan`, with
this array as data.
"""
return op.arctan(self, *args, **kwargs)
[docs] def degrees(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`degrees`.
The arguments are the same as for :py:func:`degrees`, with
this array as data.
"""
return op.degrees(self, *args, **kwargs)
[docs] def radians(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`radians`.
The arguments are the same as for :py:func:`radians`, with
this array as data.
"""
return op.radians(self, *args, **kwargs)
[docs] def sinh(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`sinh`.
The arguments are the same as for :py:func:`sinh`, with
this array as data.
"""
return op.sinh(self, *args, **kwargs)
[docs] def cosh(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`cosh`.
The arguments are the same as for :py:func:`cosh`, with
this array as data.
"""
return op.cosh(self, *args, **kwargs)
[docs] def tanh(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`tanh`.
The arguments are the same as for :py:func:`tanh`, with
this array as data.
"""
return op.tanh(self, *args, **kwargs)
[docs] def arcsinh(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`arcsinh`.
The arguments are the same as for :py:func:`arcsinh`, with
this array as data.
"""
return op.arcsinh(self, *args, **kwargs)
[docs] def arccosh(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`arccosh`.
The arguments are the same as for :py:func:`arccosh`, with
this array as data.
"""
return op.arccosh(self, *args, **kwargs)
[docs] def arctanh(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`arctanh`.
The arguments are the same as for :py:func:`arctanh`, with
this array as data.
"""
return op.arctanh(self, *args, **kwargs)
[docs] def exp(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`exp`.
The arguments are the same as for :py:func:`exp`, with
this array as data.
"""
return op.exp(self, *args, **kwargs)
[docs] def expm1(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`expm1`.
The arguments are the same as for :py:func:`expm1`, with
this array as data.
"""
return op.expm1(self, *args, **kwargs)
[docs] def log(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`log`.
The arguments are the same as for :py:func:`log`, with
this array as data.
"""
return op.log(self, *args, **kwargs)
[docs] def log10(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`log10`.
The arguments are the same as for :py:func:`log10`, with
this array as data.
"""
return op.log10(self, *args, **kwargs)
[docs] def log2(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`log2`.
The arguments are the same as for :py:func:`log2`, with
this array as data.
"""
return op.log2(self, *args, **kwargs)
[docs] def log1p(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`log1p`.
The arguments are the same as for :py:func:`log1p`, with
this array as data.
"""
return op.log1p(self, *args, **kwargs)
[docs] def sqrt(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`sqrt`.
The arguments are the same as for :py:func:`sqrt`, with
this array as data.
"""
return op.sqrt(self, *args, **kwargs)
[docs] def rsqrt(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`rsqrt`.
The arguments are the same as for :py:func:`rsqrt`, with
this array as data.
"""
return op.rsqrt(self, *args, **kwargs)
[docs] def cbrt(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`cbrt`.
The arguments are the same as for :py:func:`cbrt`, with
this array as data.
"""
return op.cbrt(self, *args, **kwargs)
[docs] def rcbrt(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`rcbrt`.
The arguments are the same as for :py:func:`rcbrt`, with
this array as data.
"""
return op.rcbrt(self, *args, **kwargs)
[docs] def square(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`square`.
The arguments are the same as for :py:func:`square`, with
this array as data.
"""
return op.square(self, *args, **kwargs)
[docs] def reciprocal(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`reciprocal`.
The arguments are the same as for :py:func:`reciprocal`, with
this array as data.
"""
return op.reciprocal(self, *args, **kwargs)
[docs] def relu(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`relu`.
The arguments are the same as for :py:func:`relu`, with
this array as data.
"""
return op.relu(self, *args, **kwargs)
[docs] def sigmoid(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`sigmoid`.
The arguments are the same as for :py:func:`sigmoid`, with
this array as data.
"""
return op.sigmoid(self, *args, **kwargs)
[docs] def softmax(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`softmax`.
The arguments are the same as for :py:func:`softmax`, with
this array as data.
"""
return op.softmax(self, *args, **kwargs)
[docs] def log_softmax(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`log_softmax`.
The arguments are the same as for :py:func:`log_softmax`, with
this array as data.
"""
return op.log_softmax(self, *args, **kwargs)
[docs] def softmin(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`softmin`.
The arguments are the same as for :py:func:`softmin`, with
this array as data.
"""
return op.softmin(self, *args, **kwargs)
[docs] def squeeze(self, *args, **kwargs):
"""Convenience fluent method for :py:func:`squeeze`.
The arguments are the same as for :py:func:`squeeze`, with
this array as data.
"""
return op.squeeze(self, *args, **kwargs)
# pylint: disable= undefined-variable
[docs] def broadcast_to(self, shape):
"""Broadcasts the input array to a new shape.
Broadcasting is only allowed on axes with size 1. The new shape cannot change
the number of dimensions.
For example, you could broadcast from shape (2, 1) to (2, 3), but not from
shape (2, 3) to (2, 3, 3).
Parameters
----------
shape : tuple of int
The shape of the desired array.
Returns
-------
NDArray
A NDArray with the desired shape that is not sharing data with this
array, even if the new shape is the same as ``self.shape``.
Examples
--------
>>> x = mx.nd.arange(0,3).reshape((1,3,1))
>>> x.asnumpy()
array([[[ 0.],
[ 1.],
[ 2.]]], dtype=float32)
>>> y = x.broadcast_to((2,3,3))
>>> y.asnumpy()
array([[[ 0., 0., 0.],
[ 1., 1., 1.],
[ 2., 2., 2.]],
[[ 0., 0., 0.],
[ 1., 1., 1.],
[ 2., 2., 2.]]], dtype=float32)
"""
cur_shape = self.shape
err_str = 'operands could not be broadcast together with remapped shapes' \
'[original->remapped]: {} and requested shape {}'.format(cur_shape, shape)
if len(shape) < len(cur_shape):
raise ValueError(err_str)
cur_shape = (1,) * (len(shape) - len(cur_shape)) + cur_shape
cur_shape_arr = np.array(cur_shape)
broadcasting_axes = np.nonzero(cur_shape_arr != np.array(shape))
if (cur_shape_arr[broadcasting_axes] != 1).any():
raise ValueError(err_str)
if cur_shape != self.shape:
return op.broadcast_to(self.reshape(cur_shape), shape=shape)
else:
return op.broadcast_to(self, shape=tuple(shape))
# pylint: enable= undefined-variable
[docs] def broadcast_like(self, other):
"""Broadcasts the input array to the shape of other.
Broadcasting is only allowed on axes with size 1. The new shape cannot change
the number of dimensions.
For example, you could broadcast from shape (2, 1) to (2, 3), but not from
shape (2, 3) to (2, 3, 3).
Parameters
----------
other : NDArray
Array with shape of the desired array.
Returns
-------
NDArray
A NDArray with the desired shape that is not sharing data with this
array, even if the new shape is the same as ``self.shape``.
Examples
--------
>>> x = mx.nd.arange(0,3).reshape((1,3,1))
>>> x.asnumpy()
array([[[ 0.],
[ 1.],
[ 2.]]], dtype=float32)
>>> y = x.broadcast_like(mx.nd.ones((2,3,3)))
>>> y.asnumpy()
array([[[ 0., 0., 0.],
[ 1., 1., 1.],
[ 2., 2., 2.]],
[[ 0., 0., 0.],
[ 1., 1., 1.],
[ 2., 2., 2.]]], dtype=float32)
"""
return self.broadcast_to(other.shape)
[docs] def wait_to_read(self):
"""Waits until all previous write operations on the current array are finished.
This method guarantees that all previous write operations that pushed
into the backend engine for execution are actually finished.
Examples
--------
>>> import time
>>> tic = time.time()
>>> a = mx.nd.ones((1000,1000))
>>> b = mx.nd.dot(a, a)
>>> print(time.time() - tic) # doctest: +SKIP
0.003854036331176758
>>> b.wait_to_read()
>>> print(time.time() - tic) # doctest: +SKIP
0.0893700122833252
"""
check_call(_LIB.MXNDArrayWaitToRead(self.handle))
@property
def ndim(self):
"""Returns the number of dimensions of this array
Examples
--------
>>> x = mx.nd.array([1, 2, 3, 4])
>>> x.ndim
1
>>> x = mx.nd.array([[1, 2], [3, 4]])
>>> x.ndim
2
"""
return len(self.shape)
@property
def shape(self):
"""Tuple of array dimensions.
Examples
--------
>>> x = mx.nd.array([1, 2, 3, 4])
>>> x.shape
(4L,)
>>> y = mx.nd.zeros((2, 3, 4))
>>> y.shape
(2L, 3L, 4L)
"""
ndim = mx_uint()
pdata = ctypes.POINTER(mx_uint)()
check_call(_LIB.MXNDArrayGetShape(
self.handle, ctypes.byref(ndim), ctypes.byref(pdata)))
return tuple(pdata[:ndim.value]) # pylint: disable=invalid-slice-index
@property
def size(self):
"""Number of elements in the array.
Equivalent to the product of the array's dimensions.
Examples
--------
>>> import numpy as np
>>> x = mx.nd.zeros((3, 5, 2))
>>> x.size
30
>>> np.prod(x.shape)
30
"""
size = 1
for i in self.shape:
size *= i
return size
@property
def context(self):
"""Device context of the array.
Examples
--------
>>> x = mx.nd.array([1, 2, 3, 4])
>>> x.context
cpu(0)
>>> type(x.context)
>>> y = mx.nd.zeros((2,3), mx.gpu(0))
>>> y.context
gpu(0)
"""
dev_typeid = ctypes.c_int()
dev_id = ctypes.c_int()
check_call(_LIB.MXNDArrayGetContext(
self.handle, ctypes.byref(dev_typeid), ctypes.byref(dev_id)))
return Context(Context.devtype2str[dev_typeid.value], dev_id.value)
@property
def dtype(self):
"""Data-type of the array's elements.
Returns
-------
numpy.dtype
This NDArray's data type.
Examples
--------
>>> x = mx.nd.zeros((2,3))
>>> x.dtype
>>> y = mx.nd.zeros((2,3), dtype='int32')
>>> y.dtype
"""
mx_dtype = ctypes.c_int()
check_call(_LIB.MXNDArrayGetDType(
self.handle, ctypes.byref(mx_dtype)))
return _DTYPE_MX_TO_NP[mx_dtype.value]
@property
def stype(self):
"""Storage-type of the array.
"""
return _STORAGE_TYPE_ID_TO_STR[_storage_type(self.handle)]
@property
# pylint: disable= invalid-name, undefined-variable
def T(self):
"""Returns a copy of the array with axes transposed.
Equivalent to ``mx.nd.transpose(self)`` except that
self is returned if ``self.ndim < 2``.
Unlike ``numpy.ndarray.T``, this function returns a copy
rather than a view of the array unless ``self.ndim < 2``.
Examples
--------
>>> x = mx.nd.arange(0,6).reshape((2,3))
>>> x.asnumpy()
array([[ 0., 1., 2.],
[ 3., 4., 5.]], dtype=float32)
>>> x.T.asnumpy()
array([[ 0., 3.],
[ 1., 4.],
[ 2., 5.]], dtype=float32)
"""
if len(self.shape) < 2:
return self
return op.transpose(self)
# pylint: enable= invalid-name, undefined-variable
@property
def _fresh_grad(self):
"""Whether this array's corresponding gradient array
(registered via `autograd.mark_variables`) has been
updated by `autograd.backward` since last reset.
`_fresh_grad` need to be manually set to False
after consuming gradient (usually after updating this
array).
"""
out = ctypes.c_int()
check_call(_LIB.MXNDArrayGetGradState(self.handle, ctypes.byref(out)))
return out.value
@_fresh_grad.setter
def _fresh_grad(self, state):
check_call(_LIB.MXNDArraySetGradState(self.handle, ctypes.c_int(state)))
[docs] def asnumpy(self):
"""Returns a ``numpy.ndarray`` object with value copied from this array.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = x.asnumpy()
>>> type(y)
>>> y
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> z = mx.nd.ones((2,3), dtype='int32')
>>> z.asnumpy()
array([[1, 1, 1],
[1, 1, 1]], dtype=int32)
"""
data = np.empty(self.shape, dtype=self.dtype)
check_call(_LIB.MXNDArraySyncCopyToCPU(
self.handle,
data.ctypes.data_as(ctypes.c_void_p),
ctypes.c_size_t(data.size)))
return data
[docs] def asscalar(self):
"""Returns a scalar whose value is copied from this array.
This function is equivalent to ``self.asnumpy()[0]``. This NDArray must have shape (1,).
Examples
--------
>>> x = mx.nd.ones((1,), dtype='int32')
>>> x.asscalar()
1
>>> type(x.asscalar())
"""
if self.shape != (1,):
raise ValueError("The current array is not a scalar")
return self.asnumpy()[0]
[docs] def astype(self, dtype, copy=True):
"""Returns a copy of the array after casting to a specified type.
Parameters
----------
dtype : numpy.dtype or str
The type of the returned array.
copy : bool
Default `True`. By default, astype always returns a newly
allocated ndarray on the same context. If this is set to
`False`, and the dtype requested is the same as the ndarray's
dtype, the ndarray is returned instead of a copy.
Returns
-------
NDArray, CSRNDArray or RowSparseNDArray
The copied array after casting to the specified type, or
the same array if copy=False and dtype is the same as the input
array.
Examples
--------
>>> x = mx.nd.zeros((2,3), dtype='float32')
>>> y = x.astype('int32')
>>> y.dtype
"""
if not copy and np.dtype(dtype) == self.dtype:
return self
res = empty(self.shape, ctx=self.context, dtype=dtype)
self.copyto(res)
return res
[docs] def copyto(self, other):
"""Copies the value of this array to another array.
If ``other`` is a ``NDArray`` object, then ``other.shape`` and
``self.shape`` should be the same. This function copies the value from
``self`` to ``other``.
If ``other`` is a context, a new ``NDArray`` will be first created on
the target context, and the value of ``self`` is copied.
Parameters
----------
other : NDArray or Context
The destination array or context.
Returns
-------
NDArray, CSRNDArray or RowSparseNDArray
The copied array. If ``other`` is an ``NDArray``, then the return value
and ``other`` will point to the same ``NDArray``.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.zeros((2,3), mx.gpu(0))
>>> z = x.copyto(y)
>>> z is y
True
>>> y.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> y.copyto(mx.gpu(0))
"""
if isinstance(other, NDArray):
if other.handle is self.handle:
warnings.warn('You are attempting to copy an array to itself', RuntimeWarning)
return False
return _internal._copyto(self, out=other)
elif isinstance(other, Context):
hret = NDArray(_new_alloc_handle(self.shape, other, True, self.dtype))
return _internal._copyto(self, out=hret)
else:
raise TypeError('copyto does not support type ' + str(type(other)))
[docs] def copy(self):
"""Makes a copy of this ``NDArray``, keeping the same context.
Returns
-------
NDArray, CSRNDArray or RowSparseNDArray
The copied array
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = x.copy()
>>> y.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
"""
return self.copyto(self.context)
[docs] def as_in_context(self, context):
"""Returns an array on the target device with the same value as this array.
If the target context is the same as ``self.context``, then ``self`` is
returned. Otherwise, a copy is made.
Parameters
----------
context : Context
The target context.
Returns
-------
NDArray, CSRNDArray or RowSparseNDArray
The target array.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = x.as_in_context(mx.cpu())
>>> y is x
True
>>> z = x.as_in_context(mx.gpu(0))
>>> z is x
False
"""
if self.context == context:
return self
return self.copyto(context)
[docs] def attach_grad(self, grad_req='write', stype=None):
"""Attach a gradient buffer to this NDArray, so that `backward`
can compute gradient with respect to it.
Parameters
----------
grad_req : {'write', 'add', 'null'}
How gradient will be accumulated.
- 'write': gradient will be overwritten on every backward.
- 'add': gradient will be added to existing value on every backward.
- 'null': do not compute gradient for this NDArray.
stype : str, optional
The storage type of the gradient array. Defaults to the same stype of this NDArray.
"""
from . import zeros as _zeros
if stype is not None:
grad = _zeros(self.shape, stype=stype)
else:
grad = op.zeros_like(self) # pylint: disable=undefined-variable
grad_req = _GRAD_REQ_MAP[grad_req]
check_call(_LIB.MXAutogradMarkVariables(
1, ctypes.pointer(self.handle),
ctypes.pointer(mx_uint(grad_req)),
ctypes.pointer(grad.handle)))
@property
def grad(self):
"""Returns gradient buffer attached to this NDArray."""
from . import _ndarray_cls
hdl = NDArrayHandle()
check_call(_LIB.MXNDArrayGetGrad(self.handle, ctypes.byref(hdl)))
if hdl.value is None:
return None
return _ndarray_cls(hdl)
[docs] def detach(self):
"""Returns a new NDArray, detached from the current graph."""
from . import _ndarray_cls
hdl = NDArrayHandle()
check_call(_LIB.MXNDArrayDetach(self.handle, ctypes.byref(hdl)))
return _ndarray_cls(hdl)
[docs] def backward(self, out_grad=None, retain_graph=False, train_mode=True):
"""Compute the gradients of this NDArray w.r.t variables.
Parameters
----------
out_grad : NDArray, optional
Gradient with respect to head.
retain_graph : bool, optional
Whether to retain the computaion graph for another backward
pass on the same graph. By default the computaion history
is cleared.
train_mode : bool, optional
Whether to compute gradient for training or inference.
"""
if out_grad is None:
ograd_handles = [NDArrayHandle(0)]
else:
ograd_handles = [out_grad.handle]
check_call(_LIB.MXAutogradBackwardEx(
1, c_handle_array([self]),
c_array(NDArrayHandle, ograd_handles),
0,
ctypes.c_void_p(0),
ctypes.c_int(retain_graph),
ctypes.c_int(0),
ctypes.c_int(train_mode),
ctypes.c_void_p(0),
ctypes.c_void_p(0)))
[docs] def tostype(self, stype):
"""Return a copy of the array with chosen storage type.
See Also
----------
:meth:`mxnet.ndarray.cast_storage`.
Returns
-------
NDArray, CSRNDArray or RowSparseNDArray
A copy of the array with the chosen storage stype
"""
return op.cast_storage(self, stype=stype)
[docs] def to_dlpack_for_read(self):
"""Returns a reference view of NDArray that represents as DLManagedTensor until
all previous write operations on the current array are finished.
Returns
-------
PyCapsule (the pointer of DLManagedTensor)
a reference view of NDArray that represents as DLManagedTensor.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.to_dlpack_for_read(x)
>>> type(y)
>>> z = mx.nd.from_dlpack(y)
>>> z
[[1. 1. 1.]
[1. 1. 1.]]
"""
return to_dlpack_for_read(self)
[docs] def to_dlpack_for_write(self):
"""Returns a reference view of NDArray that represents as DLManagedTensor until
all previous read/write operations on the current array are finished.
Returns
-------
PyCapsule (the pointer of DLManagedTensor)
a reference view of NDArray that represents as DLManagedTensor.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> w = mx.nd.to_dlpack_for_write(x)
>>> type(w)
>>> u = mx.nd.from_dlpack(w)
>>> u += 1
>>> x
[[2. 2. 2.]
[2. 2. 2.]]
"""
return to_dlpack_for_write(self)
def _get_indexing_dispatch_code(key):
"""Returns a dispatch code for calling basic or advanced indexing functions."""
if isinstance(key, (NDArray, np.ndarray)):
return _NDARRAY_ADVANCED_INDEXING
elif isinstance(key, list):
# TODO(junwu): Add support for nested lists besides integer list
for i in key:
if not isinstance(i, integer_types):
raise TypeError('Indexing NDArray only supports a list of integers as index'
' when key is of list type, received element=%s of type=%s'
% (str(i), str(type(i))))
return _NDARRAY_ADVANCED_INDEXING
elif isinstance(key, (integer_types, py_slice)):
return _NDARRAY_BASIC_INDEXING
elif isinstance(key, tuple):
for idx in key:
if isinstance(idx, (NDArray, np.ndarray, list, tuple)):
return _NDARRAY_ADVANCED_INDEXING
elif not isinstance(idx, (py_slice, integer_types)):
raise ValueError("NDArray does not support slicing with key %s of type %s."
% (str(idx), str(type(idx))))
return _NDARRAY_BASIC_INDEXING
else:
return _NDARRAY_UNSUPPORTED_INDEXING
def _get_index_range(start, stop, length, step=1):
"""Given start, stop, step and array length, return
absolute values of start, stop, and step for generating index range.
The returned values have been compensated by adding length if they
are less than zero for all the cases but slice(None, None, -1).
Note that the returned value of stop is not necessarily >= 0, since
absolute stop is -1 in the case of slice(None, None, -1)."""
if step == 0:
raise ValueError('step size cannot be zero')
if length < 0:
raise ValueError('array length cannot be less than zero')
if step is None:
step = 1
if start is None:
if step > 0:
start = 0
else:
start = length - 1
elif start < 0:
start += length
if start < 0:
raise IndexError('Slicing start %d exceeds limit of %d' % (start-length, length))
elif start >= length:
raise IndexError('Slicing start %d exceeds limit of %d' % (start, length))
if stop is None:
if step > 0:
stop = length
else:
# this supports case such as ::-1
# stop = -1 here refers to the element before index 0,
# instead of the last element in the array
stop = -1
elif stop < 0:
stop += length
if stop < 0:
raise IndexError('Slicing stop %d exceeds limit of %d' % (stop-length, length))
elif stop > length:
raise IndexError('Slicing stop %d exceeds limit of %d' % (stop, length))
return start, stop, step
def _get_oshape_of_gather_nd_op(dshape, ishape):
"""Given data and index shapes, get the output `NDArray` shape.
This basically implements the infer shape logic of op gather_nd."""
assert len(dshape) > 0 and len(ishape) > 0
oshape = list(ishape[1:])
if ishape[0] < len(dshape):
oshape.extend(dshape[ishape[0]:])
return tuple(oshape)
def _get_dim_size(start, stop, step):
"""Given start, stop, and stop, calculate the number of elements
of this slice."""
assert step != 0
if step > 0:
assert start < stop
dim_size = (stop - start - 1) // step + 1
else:
assert stop < start
dim_size = (start - stop - 1) // (-step) + 1
return dim_size
def _get_broadcast_shape(shape1, shape2):
"""Given two shapes that are not identical, find the shape
that both input shapes can broadcast to."""
if shape1 == shape2:
return shape1
length1 = len(shape1)
length2 = len(shape2)
if length1 > length2:
shape = list(shape1)
else:
shape = list(shape2)
i = max(length1, length2) - 1
for a, b in zip(shape1[::-1], shape2[::-1]):
if a != 1 and b != 1 and a != b:
raise ValueError('shape1=%s is not broadcastable to shape2=%s' % (shape1, shape2))
shape[i] = max(a, b)
i -= 1
return tuple(shape)
[docs]def onehot_encode(indices, out):
"""One-hot encoding indices into matrix out.
.. note:: `onehot_encode` is deprecated. Use `one_hot` instead.
"""
# pylint: disable= no-member, protected-access
return _internal._onehot_encode(indices, out, out=out)
# pylint: enable= no-member, protected-access
[docs]def ones(shape, ctx=None, dtype=None, **kwargs):
"""Returns a new array filled with all ones, with the given shape and type.
Parameters
----------
shape : int or tuple of int or list of int
The shape of the empty array.
ctx : Context, optional
An optional device context.
Defaults to the current default context (``mxnet.context.current_context()``).
dtype : str or numpy.dtype, optional
An optional value type (default is `float32`).
out : NDArray, optional
The output NDArray (default is `None`).
Returns
-------
NDArray
A new array of the specified shape filled with all ones.
Examples
--------
>>> mx.nd.ones(1).asnumpy()
array([ 1.], dtype=float32)
>>> mx.nd.ones((1,2), mx.gpu(0))
>>> mx.nd.ones((1,2), dtype='float16').asnumpy()
array([[ 1., 1.]], dtype=float16)
"""
# pylint: disable= unused-argument
if ctx is None:
ctx = current_context()
dtype = mx_real_t if dtype is None else dtype
# pylint: disable= no-member, protected-access
return _internal._ones(shape=shape, ctx=ctx, dtype=dtype, **kwargs)
# pylint: enable= no-member, protected-access
[docs]def full(shape, val, ctx=None, dtype=mx_real_t, out=None):
"""Returns a new array of given shape and type, filled with the given value `val`.
Parameters
--------
shape : int or tuple of int
The shape of the new array.
val : scalar
Fill value.
ctx : Context, optional
Device context (default is the current default context).
dtype : `str` or `numpy.dtype`, optional
The data type of the returned `NDArray`. The default datatype is `float32`.
out : NDArray, optional
The output NDArray (default is `None`).
Returns
-------
NDArray
`NDArray` filled with `val`, with the given shape, ctx, and dtype.
Examples
--------
>>> mx.nd.full(1, 2.0).asnumpy()
array([ 2.], dtype=float32)
>>> mx.nd.full((1, 2), 2.0, mx.gpu(0))
>>> mx.nd.full((1, 2), 2.0, dtype='float16').asnumpy()
array([[ 2., 2.]], dtype=float16)
"""
out = empty(shape, ctx, dtype) if out is None else out
out[:] = val
return out
def array(source_array, ctx=None, dtype=None):
"""Creates an array from any object exposing the array interface.
Parameters
----------
source_array : array_like
An object exposing the array interface, an object whose `__array__`
method returns an array, or any (nested) sequence.
ctx : Context, optional
Device context (default is the current default context).
dtype : str or numpy.dtype, optional
The data type of the output array. The default dtype is ``source_array.dtype``
if `source_array` is an `NDArray`, `float32` otherwise.
Returns
-------
NDArray
An `NDArray` with the same contents as the `source_array`.
"""
if isinstance(source_array, NDArray):
dtype = source_array.dtype if dtype is None else dtype
else:
dtype = mx_real_t if dtype is None else dtype
if not isinstance(source_array, np.ndarray):
try:
source_array = np.array(source_array, dtype=dtype)
except:
raise TypeError('source_array must be array like object')
arr = empty(source_array.shape, ctx, dtype)
arr[:] = source_array
return arr
[docs]def moveaxis(tensor, source, destination):
"""Moves the `source` axis into the `destination` position
while leaving the other axes in their original order
Parameters
----------
tensor : mx.nd.array
The array which axes should be reordered
source : int
Original position of the axes to move.
destination : int
Destination position for each of the original axes.
Returns
-------
result : mx.nd.array
Array with moved axes.
Examples
--------
>>> X = mx.nd.array([[1, 2, 3], [4, 5, 6]])
>>> mx.nd.moveaxis(X, 0, 1).shape
(3L, 2L)
"""
axes = list(range(tensor.ndim))
try:
axes.pop(source)
except IndexError:
raise ValueError('Source should verify 0 <= source < tensor.ndim'
'Got %d' % source)
try:
axes.insert(destination, source)
except IndexError:
raise ValueError('Destination should verify 0 <= destination < tensor.ndim'
'Got %d' % destination)
return op.transpose(tensor, axes)
# pylint: disable= no-member, protected-access, too-many-arguments, redefined-outer-name
[docs]def arange(start, stop=None, step=1.0, repeat=1, infer_range=False, ctx=None, dtype=mx_real_t):
"""Returns evenly spaced values within a given interval.
Values are generated within the half-open interval [`start`, `stop`). In other
words, the interval includes `start` but excludes `stop`. The function is
similar to the built-in Python function `range` and to `numpy.arange`,
but returns an `NDArray`.
Parameters
----------
start : number, optional
Start of interval. The default start value is 0.
stop : number
End of interval.
step : number, optional
Spacing between values. The default step size is 1.
repeat : int, optional
Number of times to repeat each element. The default repeat count is 1.
infer_range : boolean, optional
When set to True, infer the stop position from the start, step,
repeat, and output tensor size.
ctx : Context, optional
Device context. Default context is the current default context.
dtype : str or numpy.dtype, optional
The data type of the `NDArray`. The default datatype is `np.float32`.
Returns
-------
NDArray
`NDArray` of evenly spaced values in the specified range.
Examples
--------
>>> mx.nd.arange(3).asnumpy()
array([ 0., 1., 2.], dtype=float32)
>>> mx.nd.arange(2, 6).asnumpy()
array([ 2., 3., 4., 5.], dtype=float32)
>>> mx.nd.arange(2, 6, step=2).asnumpy()
array([ 2., 4.], dtype=float32)
>>> mx.nd.arange(2, 6, step=1.5, repeat=2).asnumpy()
array([ 2. , 2. , 3.5, 3.5, 5. , 5. ], dtype=float32)
>>> mx.nd.arange(2, 6, step=2, repeat=3, dtype='int32').asnumpy()
array([2, 2, 2, 4, 4, 4], dtype=int32)
"""
if ctx is None:
ctx = current_context()
return _internal._arange(start=start, stop=stop, step=step, repeat=repeat,
infer_range=infer_range, dtype=dtype, ctx=str(ctx))
# pylint: enable= no-member, protected-access, too-many-arguments
#pylint: disable= too-many-arguments, no-member, protected-access
def _ufunc_helper(lhs, rhs, fn_array, fn_scalar, lfn_scalar, rfn_scalar=None):
""" Helper function for element-wise operation.
The function will perform numpy-like broadcasting if needed and call different functions.
Parameters
--------
lhs : NDArray or numeric value
Left-hand side operand.
rhs : NDArray or numeric value
Right-hand operand,
fn_array : function
Function to be called if both lhs and rhs are of ``NDArray`` type.
fn_scalar : function
Function to be called if both lhs and rhs are numeric values.
lfn_scalar : function
Function to be called if lhs is ``NDArray`` while rhs is numeric value
rfn_scalar : function
Function to be called if lhs is numeric value while rhs is ``NDArray``;
if none is provided, then the function is commutative, so rfn_scalar is equal to lfn_scalar
Returns
--------
NDArray
result array
"""
if isinstance(lhs, numeric_types):
if isinstance(rhs, numeric_types):
return fn_scalar(lhs, rhs)
else:
if rfn_scalar is None:
# commutative function
return lfn_scalar(rhs, float(lhs))
else:
return rfn_scalar(rhs, float(lhs))
elif isinstance(rhs, numeric_types):
return lfn_scalar(lhs, float(rhs))
elif isinstance(rhs, NDArray):
return fn_array(lhs, rhs)
else:
raise TypeError('type %s not supported' % str(type(rhs)))
#pylint: enable= too-many-arguments, no-member, protected-access
[docs]def add(lhs, rhs):
"""Returns element-wise sum of the input arrays with broadcasting.
Equivalent to ``lhs + rhs``, ``mx.nd.broadcast_add(lhs, rhs)`` and
``mx.nd.broadcast_plus(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First array to be added.
rhs : scalar or mxnet.ndarray.array
Second array to be added.
If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
The element-wise sum of the input arrays.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.arange(2).reshape((2,1))
>>> z = mx.nd.arange(2).reshape((1,2))
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> y.asnumpy()
array([[ 0.],
[ 1.]], dtype=float32)
>>> z.asnumpy()
array([[ 0., 1.]], dtype=float32)
>>> (x+2).asnumpy()
array([[ 3., 3., 3.],
[ 3., 3., 3.]], dtype=float32)
>>> (x+y).asnumpy()
array([[ 1., 1., 1.],
[ 2., 2., 2.]], dtype=float32)
>>> mx.nd.add(x,y).asnumpy()
array([[ 1., 1., 1.],
[ 2., 2., 2.]], dtype=float32)
>>> (z + y).asnumpy()
array([[ 0., 1.],
[ 1., 2.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_add,
operator.add,
_internal._plus_scalar,
None)
# pylint: enable= no-member, protected-access
[docs]def subtract(lhs, rhs):
"""Returns element-wise difference of the input arrays with broadcasting.
Equivalent to ``lhs - rhs``, ``mx.nd.broadcast_sub(lhs, rhs)`` and
``mx.nd.broadcast_minus(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First array to be subtracted.
rhs : scalar or mxnet.ndarray.array
Second array to be subtracted.
If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
The element-wise difference of the input arrays.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.arange(2).reshape((2,1))
>>> z = mx.nd.arange(2).reshape((1,2))
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> y.asnumpy()
array([[ 0.],
[ 1.]], dtype=float32)
>>> z.asnumpy()
array([[ 0., 1.]], dtype=float32)
>>> (x-2).asnumpy()
array([[-1., -1., -1.],
[-1., -1., -1.]], dtype=float32)
>>> (x-y).asnumpy()
array([[ 1., 1., 1.],
[ 0., 0., 0.]], dtype=float32)
>>> mx.nd.subtract(x,y).asnumpy()
array([[ 1., 1., 1.],
[ 0., 0., 0.]], dtype=float32)
>>> (z-y).asnumpy()
array([[ 0., 1.],
[-1., 0.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_sub,
operator.sub,
_internal._minus_scalar,
_internal._rminus_scalar)
# pylint: enable= no-member, protected-access
[docs]def multiply(lhs, rhs):
"""Returns element-wise product of the input arrays with broadcasting.
Equivalent to ``lhs * rhs`` and ``mx.nd.broadcast_mul(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First array to be multiplied.
rhs : scalar or mxnet.ndarray.array
Second array to be multiplied.
If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
The element-wise multiplication of the input arrays.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.arange(2).reshape((2,1))
>>> z = mx.nd.arange(2).reshape((1,2))
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> y.asnumpy()
array([[ 0.],
[ 1.]], dtype=float32)
>>> z.asnumpy()
array([[ 0., 1.]], dtype=float32)
>>> (x*2).asnumpy()
array([[ 2., 2., 2.],
[ 2., 2., 2.]], dtype=float32)
>>> (x*y).asnumpy()
array([[ 0., 0., 0.],
[ 1., 1., 1.]], dtype=float32)
>>> mx.nd.multiply(x, y).asnumpy()
array([[ 0., 0., 0.],
[ 1., 1., 1.]], dtype=float32)
>>> (z*y).asnumpy()
array([[ 0., 0.],
[ 0., 1.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_mul,
operator.mul,
_internal._mul_scalar,
None)
# pylint: enable= no-member, protected-access
[docs]def divide(lhs, rhs):
"""Returns element-wise division of the input arrays with broadcasting.
Equivalent to ``lhs / rhs`` and ``mx.nd.broadcast_div(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First array in division.
rhs : scalar or mxnet.ndarray.array
Second array in division.
The arrays to be divided. If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
The element-wise division of the input arrays.
Examples
--------
>>> x = mx.nd.ones((2,3))*6
>>> y = mx.nd.ones((2,1))*2
>>> x.asnumpy()
array([[ 6., 6., 6.],
[ 6., 6., 6.]], dtype=float32)
>>> y.asnumpy()
array([[ 2.],
[ 2.]], dtype=float32)
>>> x/2
>>> (x/3).asnumpy()
array([[ 2., 2., 2.],
[ 2., 2., 2.]], dtype=float32)
>>> (x/y).asnumpy()
array([[ 3., 3., 3.],
[ 3., 3., 3.]], dtype=float32)
>>> mx.nd.divide(x,y).asnumpy()
array([[ 3., 3., 3.],
[ 3., 3., 3.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_div,
operator.truediv,
_internal._div_scalar,
_internal._rdiv_scalar)
# pylint: enable= no-member, protected-access
[docs]def modulo(lhs, rhs):
"""Returns element-wise modulo of the input arrays with broadcasting.
Equivalent to ``lhs % rhs`` and ``mx.nd.broadcast_mod(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First array in modulo.
rhs : scalar or mxnet.ndarray.array
Second array in modulo.
The arrays to be taken modulo. If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
The element-wise modulo of the input arrays.
Examples
--------
>>> x = mx.nd.ones((2,3))*6
>>> y = mx.nd.ones((2,1))*4
>>> x.asnumpy()
array([[ 6., 6., 6.],
[ 6., 6., 6.]], dtype=float32)
>>> y.asnumpy()
array([[ 4.],
[ 4.]], dtype=float32)
>>> x%5
>>> (x%5).asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> (x%y).asnumpy()
array([[ 2., 2., 2.],
[ 2., 2., 2.]], dtype=float32)
>>> mx.nd.modulo(x,y).asnumpy()
array([[ 2., 2., 2.],
[ 2., 2., 2.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_mod,
operator.mod,
_internal._mod_scalar,
_internal._rmod_scalar)
# pylint: enable= no-member, protected-access
[docs]def power(base, exp):
"""Returns result of first array elements raised to powers from second array, element-wise
with broadcasting.
Equivalent to ``base ** exp`` and ``mx.nd.broadcast_power(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
base : scalar or NDArray
The base array
exp : scalar or NDArray
The exponent array. If ``base.shape != exp.shape``, they must be
broadcastable to a common shape.
Returns
--------
NDArray
The bases in x raised to the exponents in y.
Examples
--------
>>> x = mx.nd.ones((2,3))*2
>>> y = mx.nd.arange(1,3).reshape((2,1))
>>> z = mx.nd.arange(1,3).reshape((2,1))
>>> x.asnumpy()
array([[ 2., 2., 2.],
[ 2., 2., 2.]], dtype=float32)
>>> y.asnumpy()
array([[ 1.],
[ 2.]], dtype=float32)
>>> z.asnumpy()
array([[ 1.],
[ 2.]], dtype=float32)
>>> (x**2).asnumpy()
array([[ 4., 4., 4.],
[ 4., 4., 4.]], dtype=float32)
>>> (x**y).asnumpy()
array([[ 2., 2., 2.],
[ 4., 4., 4.]], dtype=float32)
>>> mx.nd.power(x,y).asnumpy()
array([[ 2., 2., 2.],
[ 4., 4., 4.]], dtype=float32)
>>> (z**y).asnumpy()
array([[ 1.],
[ 4.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
base,
exp,
op.broadcast_power,
operator.pow,
_internal._power_scalar,
_internal._rpower_scalar)
# pylint: enable= no-member, protected-access
[docs]def maximum(lhs, rhs):
"""Returns element-wise maximum of the input arrays with broadcasting.
Equivalent to ``mx.nd.broadcast_maximum(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First array to be compared.
rhs : scalar or mxnet.ndarray.array
Second array to be compared. If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
The element-wise maximum of the input arrays.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.arange(2).reshape((2,1))
>>> z = mx.nd.arange(2).reshape((1,2))
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> y.asnumpy()
array([[ 0.],
[ 1.]], dtype=float32)
>>> z.asnumpy()
array([[ 0., 1.]], dtype=float32)
>>> mx.nd.maximum(x, 2).asnumpy()
array([[ 2., 2., 2.],
[ 2., 2., 2.]], dtype=float32)
>>> mx.nd.maximum(x, y).asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> mx.nd.maximum(y, z).asnumpy()
array([[ 0., 1.],
[ 1., 1.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_maximum,
lambda x, y: x if x > y else y,
_internal._maximum_scalar,
None)
# pylint: enable= no-member, protected-access
[docs]def minimum(lhs, rhs):
"""Returns element-wise minimum of the input arrays with broadcasting.
Equivalent to ``mx.nd.broadcast_minimum(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First array to be compared.
rhs : scalar or mxnet.ndarray.array
Second array to be compared. If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
The element-wise minimum of the input arrays.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.arange(2).reshape((2,1))
>>> z = mx.nd.arange(2).reshape((1,2))
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> y.asnumpy()
array([[ 0.],
[ 1.]], dtype=float32)
>>> z.asnumpy()
array([[ 0., 1.]], dtype=float32)
>>> mx.nd.minimum(x, 2).asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> mx.nd.minimum(x, y).asnumpy()
array([[ 0., 0., 0.],
[ 1., 1., 1.]], dtype=float32)
>>> mx.nd.minimum(z, y).asnumpy()
array([[ 0., 0.],
[ 0., 1.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_minimum,
lambda x, y: x if x < y else y,
_internal._minimum_scalar,
None)
# pylint: enable= no-member, protected-access
[docs]def equal(lhs, rhs):
"""Returns the result of element-wise **equal to** (==) comparison operation with
broadcasting.
For each element in input arrays, return 1(true) if corresponding elements are same,
otherwise return 0(false).
Equivalent to ``lhs == rhs`` and ``mx.nd.broadcast_equal(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First array to be compared.
rhs : scalar or mxnet.ndarray.array
Second array to be compared. If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
Output array of boolean values.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.arange(2).reshape((2,1))
>>> z = mx.nd.arange(2).reshape((1,2))
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> y.asnumpy()
array([[ 0.],
[ 1.]], dtype=float32)
>>> z.asnumpy()
array([[ 0., 1.]], dtype=float32)
>>> (x == 1).asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> (x == y).asnumpy()
array([[ 0., 0., 0.],
[ 1., 1., 1.]], dtype=float32)
>>> mx.nd.equal(x,y).asnumpy()
array([[ 0., 0., 0.],
[ 1., 1., 1.]], dtype=float32)
>>> (z == y).asnumpy()
array([[ 1., 0.],
[ 0., 1.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_equal,
lambda x, y: 1 if x == y else 0,
_internal._equal_scalar,
None)
# pylint: enable= no-member, protected-access
[docs]def not_equal(lhs, rhs):
"""Returns the result of element-wise **not equal to** (!=) comparison operation
with broadcasting.
For each element in input arrays, return 1(true) if corresponding elements are different,
otherwise return 0(false).
Equivalent to ``lhs != rhs`` and ``mx.nd.broadcast_not_equal(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First array to be compared.
rhs : scalar or mxnet.ndarray.array
Second array to be compared. If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
Output array of boolean values.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.arange(2).reshape((2,1))
>>> z = mx.nd.arange(2).reshape((1,2))
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> y.asnumpy()
array([[ 0.],
[ 1.]], dtype=float32)
>>> z.asnumpy()
array([[ 0., 1.]], dtype=float32)
>>> (z == y).asnumpy()
array([[ 1., 0.],
[ 0., 1.]], dtype=float32)
>>> (x != 1).asnumpy()
array([[ 0., 0., 0.],
[ 0., 0., 0.]], dtype=float32)
>>> (x != y).asnumpy()
array([[ 1., 1., 1.],
[ 0., 0., 0.]], dtype=float32)
>>> mx.nd.not_equal(x, y).asnumpy()
array([[ 1., 1., 1.],
[ 0., 0., 0.]], dtype=float32)
>>> (z != y).asnumpy()
array([[ 0., 1.],
[ 1., 0.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_not_equal,
lambda x, y: 1 if x != y else 0,
_internal._not_equal_scalar,
None)
# pylint: enable= no-member, protected-access
[docs]def greater(lhs, rhs):
"""Returns the result of element-wise **greater than** (>) comparison operation
with broadcasting.
For each element in input arrays, return 1(true) if lhs elements are greater than rhs,
otherwise return 0(false).
Equivalent to ``lhs > rhs`` and ``mx.nd.broadcast_greater(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First array to be compared.
rhs : scalar or mxnet.ndarray.array
Second array to be compared. If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
Output array of boolean values.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.arange(2).reshape((2,1))
>>> z = mx.nd.arange(2).reshape((1,2))
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> y.asnumpy()
array([[ 0.],
[ 1.]], dtype=float32)
>>> z.asnumpy()
array([[ 0., 1.]], dtype=float32)
>>> (x > 1).asnumpy()
array([[ 0., 0., 0.],
[ 0., 0., 0.]], dtype=float32)
>>> (x > y).asnumpy()
array([[ 1., 1., 1.],
[ 0., 0., 0.]], dtype=float32)
>>> mx.nd.greater(x, y).asnumpy()
array([[ 1., 1., 1.],
[ 0., 0., 0.]], dtype=float32)
>>> (z > y).asnumpy()
array([[ 0., 1.],
[ 0., 0.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_greater,
lambda x, y: 1 if x > y else 0,
_internal._greater_scalar,
_internal._lesser_scalar)
# pylint: enable= no-member, protected-access
[docs]def greater_equal(lhs, rhs):
"""Returns the result of element-wise **greater than or equal to** (>=) comparison
operation with broadcasting.
For each element in input arrays, return 1(true) if lhs elements are greater than equal to rhs,
otherwise return 0(false).
Equivalent to ``lhs >= rhs`` and ``mx.nd.broadcast_greater_equal(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First array to be compared.
rhs : scalar or mxnet.ndarray.array
Second array to be compared. If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
Output array of boolean values.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.arange(2).reshape((2,1))
>>> z = mx.nd.arange(2).reshape((1,2))
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> y.asnumpy()
array([[ 0.],
[ 1.]], dtype=float32)
>>> z.asnumpy()
array([[ 0., 1.]], dtype=float32)
>>> (x >= 1).asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> (x >= y).asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> mx.nd.greater_equal(x, y).asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> (z >= y).asnumpy()
array([[ 1., 1.],
[ 0., 1.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_greater_equal,
lambda x, y: 1 if x >= y else 0,
_internal._greater_equal_scalar,
_internal._lesser_equal_scalar)
# pylint: enable= no-member, protected-access
[docs]def lesser(lhs, rhs):
"""Returns the result of element-wise **lesser than** (<) comparison operation
with broadcasting.
For each element in input arrays, return 1(true) if lhs elements are less than rhs,
otherwise return 0(false).
Equivalent to ``lhs < rhs`` and ``mx.nd.broadcast_lesser(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First array to be compared.
rhs : scalar or mxnet.ndarray.array
Second array to be compared. If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
Output array of boolean values.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.arange(2).reshape((2,1))
>>> z = mx.nd.arange(2).reshape((1,2))
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> y.asnumpy()
array([[ 0.],
[ 1.]], dtype=float32)
>>> z.asnumpy()
array([[ 0., 1.]], dtype=float32)
>>> (x < 1).asnumpy()
array([[ 0., 0., 0.],
[ 0., 0., 0.]], dtype=float32)
>>> (x < y).asnumpy()
array([[ 0., 0., 0.],
[ 0., 0., 0.]], dtype=float32)
>>> mx.nd.lesser(x, y).asnumpy()
array([[ 0., 0., 0.],
[ 0., 0., 0.]], dtype=float32)
>>> (z < y).asnumpy()
array([[ 0., 0.],
[ 1., 0.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_lesser,
lambda x, y: 1 if x < y else 0,
_internal._lesser_scalar,
_internal._greater_scalar)
# pylint: enable= no-member, protected-access
[docs]def lesser_equal(lhs, rhs):
"""Returns the result of element-wise **lesser than or equal to** (<=) comparison
operation with broadcasting.
For each element in input arrays, return 1(true) if lhs elements are
lesser than equal to rhs, otherwise return 0(false).
Equivalent to ``lhs <= rhs`` and ``mx.nd.broadcast_lesser_equal(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First array to be compared.
rhs : scalar or mxnet.ndarray.array
Second array to be compared. If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
Output array of boolean values.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.arange(2).reshape((2,1))
>>> z = mx.nd.arange(2).reshape((1,2))
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> y.asnumpy()
array([[ 0.],
[ 1.]], dtype=float32)
>>> z.asnumpy()
array([[ 0., 1.]], dtype=float32)
>>> (x <= 1).asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> (x <= y).asnumpy()
array([[ 0., 0., 0.],
[ 1., 1., 1.]], dtype=float32)
>>> mx.nd.lesser_equal(x, y).asnumpy()
array([[ 0., 0., 0.],
[ 1., 1., 1.]], dtype=float32)
>>> (z <= y).asnumpy()
array([[ 1., 0.],
[ 1., 1.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_lesser_equal,
lambda x, y: 1 if x <= y else 0,
_internal._lesser_equal_scalar,
_internal._greater_equal_scalar)
# pylint: enable= no-member, protected-access
[docs]def logical_and(lhs, rhs):
"""Returns the result of element-wise **logical and** comparison
operation with broadcasting.
For each element in input arrays, return 1(true) if lhs elements and rhs elements
are true, otherwise return 0(false).
Equivalent to ``lhs and rhs`` and ``mx.nd.broadcast_logical_and(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First input of the function.
rhs : scalar or mxnet.ndarray.array
Second input of the function. If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
Output array of boolean values.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.arange(2).reshape((2,1))
>>> z = mx.nd.arange(2).reshape((1,2))
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> y.asnumpy()
array([[ 0.],
[ 1.]], dtype=float32)
>>> z.asnumpy()
array([[ 0., 1.]], dtype=float32)
>>> mx.nd.logical_and(x, 1).asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> mx.nd.logical_and(x, y).asnumpy()
array([[ 0., 0., 0.],
[ 1., 1., 1.]], dtype=float32)
>>> mx.nd.logical_and(z, y).asnumpy()
array([[ 0., 0.],
[ 0., 1.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_logical_and,
lambda x, y: 1 if x and y else 0,
_internal._logical_and_scalar,
None)
# pylint: enable= no-member, protected-access
[docs]def logical_or(lhs, rhs):
"""Returns the result of element-wise **logical or** comparison
operation with broadcasting.
For each element in input arrays, return 1(true) if lhs elements or rhs elements
are true, otherwise return 0(false).
Equivalent to ``lhs or rhs`` and ``mx.nd.broadcast_logical_or(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First input of the function.
rhs : scalar or mxnet.ndarray.array
Second input of the function. If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
Output array of boolean values.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.arange(2).reshape((2,1))
>>> z = mx.nd.arange(2).reshape((1,2))
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> y.asnumpy()
array([[ 0.],
[ 1.]], dtype=float32)
>>> z.asnumpy()
array([[ 0., 1.]], dtype=float32)
>>> mx.nd.logical_or(x, 1).asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> mx.nd.logical_or(x, y).asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> mx.nd.logical_or(z, y).asnumpy()
array([[ 0., 1.],
[ 1., 1.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_logical_or,
lambda x, y: 1 if x or y else 0,
_internal._logical_or_scalar,
None)
# pylint: enable= no-member, protected-access
[docs]def logical_xor(lhs, rhs):
"""Returns the result of element-wise **logical xor** comparison
operation with broadcasting.
For each element in input arrays, return 1(true) if lhs elements or rhs elements
are true, otherwise return 0(false).
Equivalent to ``bool(lhs) ^ bool(rhs)`` and ``mx.nd.broadcast_logical_xor(lhs, rhs)``.
.. note::
If the corresponding dimensions of two arrays have the same size or one of them has size 1,
then the arrays are broadcastable to a common shape.
Parameters
----------
lhs : scalar or mxnet.ndarray.array
First input of the function.
rhs : scalar or mxnet.ndarray.array
Second input of the function. If ``lhs.shape != rhs.shape``, they must be
broadcastable to a common shape.
Returns
-------
NDArray
Output array of boolean values.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.arange(2).reshape((2,1))
>>> z = mx.nd.arange(2).reshape((1,2))
>>> x.asnumpy()
array([[ 1., 1., 1.],
[ 1., 1., 1.]], dtype=float32)
>>> y.asnumpy()
array([[ 0.],
[ 1.]], dtype=float32)
>>> z.asnumpy()
array([[ 0., 1.]], dtype=float32)
>>> mx.nd.logical_xor(x, y).asnumpy()
array([[ 1., 1., 1.],
[ 0., 0., 0.]], dtype=float32)
"""
# pylint: disable= no-member, protected-access
return _ufunc_helper(
lhs,
rhs,
op.broadcast_logical_xor,
lambda x, y: 1 if bool(x) ^ bool(y) else 0,
_internal._logical_xor_scalar,
None)
# pylint: enable= no-member, protected-access
[docs]def true_divide(lhs, rhs):
"""This function is similar to :meth:`divide`.
"""
return divide(lhs, rhs)
[docs]def concatenate(arrays, axis=0, always_copy=True):
"""DEPRECATED, use ``concat`` instead
Parameters
----------
arrays : list of `NDArray`
Arrays to be concatenate. They must have identical shape except
the first dimension. They also must have the same data type.
axis : int
The axis along which to concatenate.
always_copy : bool
Default `True`. When not `True`, if the arrays only contain one
`NDArray`, that element will be returned directly, avoid copying.
Returns
-------
NDArray
An `NDArray` that lives on the same context as `arrays[0].context`.
"""
assert isinstance(arrays, list)
assert len(arrays) > 0
assert isinstance(arrays[0], NDArray)
if not always_copy and len(arrays) == 1:
return arrays[0]
shape_axis = arrays[0].shape[axis]
shape_rest1 = arrays[0].shape[0:axis]
shape_rest2 = arrays[0].shape[axis+1:]
dtype = arrays[0].dtype
for arr in arrays[1:]:
shape_axis += arr.shape[axis]
assert shape_rest1 == arr.shape[0:axis]
assert shape_rest2 == arr.shape[axis+1:]
assert dtype == arr.dtype
ret_shape = shape_rest1 + (shape_axis,) + shape_rest2
ret = empty(ret_shape, ctx=arrays[0].context, dtype=dtype)
idx = 0
begin = [0 for _ in ret_shape]
end = list(ret_shape)
for arr in arrays:
if axis == 0:
ret[idx:idx+arr.shape[0]] = arr
else:
begin[axis] = idx
end[axis] = idx+arr.shape[axis]
# pylint: disable=no-member,protected-access
_internal._crop_assign(ret, arr, out=ret,
begin=tuple(begin),
end=tuple(end))
# pylint: enable=no-member,protected-access
idx += arr.shape[axis]
return ret
# pylint: disable=redefined-outer-name
[docs]def imdecode(str_img, clip_rect=(0, 0, 0, 0), out=None, index=0, channels=3, mean=None):
"""DEPRECATED, use mx.img instead
Parameters
----------
str_img : str
Binary image data
clip_rect : iterable of 4 int
Clip decoded image to rectangle (x0, y0, x1, y1).
out : NDArray
Output buffer. Can be 3 dimensional (c, h, w) or 4 dimensional (n, c, h, w).
index : int
Output decoded image to i-th slice of 4 dimensional buffer.
channels : int
Number of channels to output. Decode to grey scale when channels = 1.
mean : NDArray
Subtract mean from decode image before outputing.
"""
# pylint: disable= no-member, protected-access, too-many-arguments
if mean is None:
mean = NDArray(_new_empty_handle())
if out is None:
return _internal._imdecode(mean, index,
clip_rect[0],
clip_rect[1],
clip_rect[2],
clip_rect[3],
channels,
len(str_img),
str_img=str_img)
else:
return _internal._imdecode(mean, index,
clip_rect[0],
clip_rect[1],
clip_rect[2],
clip_rect[3],
channels,
len(str_img),
str_img=str_img,
out=out)
def zeros(shape, ctx=None, dtype=None, **kwargs):
"""Returns a new array filled with all zeros, with the given shape and type.
Parameters
----------
shape : int or tuple of int
The shape of the empty array.
ctx : Context, optional
An optional device context (default is the current default context).
dtype : str or numpy.dtype, optional
An optional value type (default is `float32`).
out : NDArray, optional
The output NDArray (default is `None`).
Returns
-------
NDArray
A created array
Examples
--------
>>> mx.nd.zeros(1).asnumpy()
array([ 0.], dtype=float32)
>>> mx.nd.zeros((1,2), mx.gpu(0))
>>> mx.nd.zeros((1,2), mx.gpu(0), 'float16').asnumpy()
array([[ 0., 0.]], dtype=float16)
"""
# pylint: disable= unused-argument
if ctx is None:
ctx = current_context()
dtype = mx_real_t if dtype is None else dtype
# pylint: disable= no-member, protected-access
return _internal._zeros(shape=shape, ctx=ctx, dtype=dtype, **kwargs)
# pylint: enable= no-member, protected-access
[docs]def eye(N, M=0, k=0, ctx=None, dtype=None, **kwargs):
"""Return a 2-D array with ones on the diagonal and zeros elsewhere.
Parameters
----------
N: int
Number of rows in the output.
M: int, optional
Number of columns in the output. If 0, defaults to N.
k: int, optional
Index of the diagonal: 0 (the default) refers to the main diagonal,
a positive value refers to an upper diagonal,
and a negative value to a lower diagonal.
ctx: Context, optional
An optional device context (default is the current default context)
dtype: str or numpy.dtype, optional
An optional value type (default is `float32`)
Returns
-------
NDArray
A created array
Examples
--------
>>> mx.nd.eye(2)
[[ 1. 0.]
[ 0. 1.]]
>>> mx.nd.eye(2, 3, 1)
[[ 0. 1. 0.]
[ 0. 0. 1.]]
"""
# pylint: disable= unused-argument
if ctx is None:
ctx = current_context()
dtype = mx_real_t if dtype is None else dtype
# pylint: disable= no-member, protected-access
return _internal._eye(N=N, M=M, k=k, ctx=ctx, dtype=dtype, **kwargs)
# pylint: enable= no-member, protected-access
def empty(shape, ctx=None, dtype=None):
"""Returns a new array of given shape and type, without initializing entries.
Parameters
----------
shape : int or tuple of int
The shape of the empty array.
ctx : Context, optional
An optional device context (default is the current default context).
dtype : str or numpy.dtype, optional
An optional value type (default is `float32`).
Returns
-------
NDArray
A created array.
"""
if isinstance(shape, int):
shape = (shape, )
if ctx is None:
ctx = current_context()
if dtype is None:
dtype = mx_real_t
return NDArray(handle=_new_alloc_handle(shape, ctx, False, dtype))
# pylint: disable= redefined-builtin
[docs]def histogram(a, bins=10, range=None):
"""Compute the histogram of the input data.
Parameters
----------
a : NDArray
Input data. The histogram is computed over the flattened array.
bins : int or sequence of scalars
If bins is an int, it defines the number of equal-width bins in the
given range (10, by default). If bins is a sequence, it defines the bin edges,
including the rightmost edge, allowing for non-uniform bin widths.
range : (float, float), optional
The lower and upper range of the bins. If not provided, range is simply (a.min(), a.max()).
Values outside the range are ignored. The first element of the range must be less than or
equal to the second. range affects the automatic bin computation as well, the range will
be equally divided by the number of bins.
"""
# pylint: disable= no-member, protected-access
if isinstance(bins, NDArray):
return _internal._histogram(data=a, bins=bins)
elif isinstance(bins, integer_types):
if range is None:
warnings.warn("range is not specified, using numpy's result "
"to ensure consistency with numpy")
res, bin_bounds = np.histogram(a.asnumpy(), bins=bins)
return array(res), array(bin_bounds)
return _internal._histogram(data=a, bin_cnt=bins, range=range)
raise ValueError("bins argument should be either an integer or an NDArray")
# pylint: enable= no-member, protected-access, redefined-builtin
PyCapsuleDestructor = ctypes.CFUNCTYPE(None, ctypes.c_void_p)
_c_str_dltensor = c_str('dltensor')
_c_str_used_dltensor = c_str('used_dltensor')
def _dlpack_deleter(pycapsule):
pycapsule = ctypes.c_void_p(pycapsule)
if ctypes.pythonapi.PyCapsule_IsValid(pycapsule, _c_str_dltensor):
ptr = ctypes.c_void_p(
ctypes.pythonapi.PyCapsule_GetPointer(pycapsule, _c_str_dltensor))
check_call(_LIB.MXNDArrayCallDLPackDeleter(ptr))
_c_dlpack_deleter = PyCapsuleDestructor(_dlpack_deleter)
[docs]def to_dlpack_for_read(data):
"""Returns a reference view of NDArray that represents as DLManagedTensor until
all previous write operations on the current array are finished.
Parameters
----------
data: NDArray
input data.
Returns
-------
PyCapsule (the pointer of DLManagedTensor)
a reference view of NDArray that represents as DLManagedTensor.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.to_dlpack_for_read(x)
>>> type(y)
>>> z = mx.nd.from_dlpack(y)
>>> z
[[1. 1. 1.]
[1. 1. 1.]]
"""
data.wait_to_read()
dlpack = DLPackHandle()
check_call(_LIB.MXNDArrayToDLPack(data.handle, ctypes.byref(dlpack)))
return ctypes.pythonapi.PyCapsule_New(dlpack, _c_str_dltensor, _c_dlpack_deleter)
[docs]def to_dlpack_for_write(data):
"""Returns a reference view of NDArray that represents as DLManagedTensor until
all previous read/write operations on the current array are finished.
Parameters
----------
data: NDArray
input data.
Returns
-------
PyCapsule (the pointer of DLManagedTensor)
a reference view of NDArray that represents as DLManagedTensor.
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> w = mx.nd.to_dlpack_for_write(x)
>>> type(w)
>>> u = mx.nd.from_dlpack(w)
>>> u += 1
>>> x
[[2. 2. 2.]
[2. 2. 2.]]
"""
check_call(_LIB.MXNDArrayWaitToWrite(data.handle))
dlpack = DLPackHandle()
check_call(_LIB.MXNDArrayToDLPack(data.handle, ctypes.byref(dlpack)))
return ctypes.pythonapi.PyCapsule_New(dlpack, _c_str_dltensor, _c_dlpack_deleter)
[docs]def from_dlpack(dlpack):
"""Returns a NDArray backed by a dlpack tensor.
Parameters
----------
dlpack: PyCapsule (the pointer of DLManagedTensor)
input data
Returns
-------
NDArray
a NDArray backed by a dlpack tensor
Examples
--------
>>> x = mx.nd.ones((2,3))
>>> y = mx.nd.to_dlpack_for_read(x)
>>> type(y)
>>> z = mx.nd.from_dlpack(y)
>>> type(z)
>>> z
[[ 1. 1. 1.]
[ 1. 1. 1.]]
>>> w = mx.nd.to_dlpack_for_write(x)
>>> type(w)
>>> u = mx.nd.from_dlpack(w)
>>> u += 1
>>> x
[[2. 2. 2.]
[2. 2. 2.]]
"""
handle = NDArrayHandle()
dlpack = ctypes.py_object(dlpack)
assert ctypes.pythonapi.PyCapsule_IsValid(dlpack, _c_str_dltensor), ValueError(
'Invalid DLPack Tensor. DLTensor capsules can be consumed only once.')
dlpack_handle = ctypes.c_void_p(ctypes.pythonapi.PyCapsule_GetPointer(dlpack, _c_str_dltensor))
check_call(_LIB.MXNDArrayFromDLPack(dlpack_handle, ctypes.byref(handle)))
# Rename PyCapsule (DLPack)
ctypes.pythonapi.PyCapsule_SetName(dlpack, _c_str_used_dltensor)
# delete the deleter of the old dlpack
ctypes.pythonapi.PyCapsule_SetDestructor(dlpack, None)
return NDArray(handle=handle)
