EVOLUTION-MANAGER
Edit File: __init__.py
# Copyright 2020 The TensorFlow Authors. All Rights Reserved. # # Licensed 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 "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # ============================================================================== """# tf.experimental.numpy: NumPy API on TensorFlow. This module provides a subset of NumPy API, built on top of TensorFlow operations. APIs are based on and have been tested with NumPy 1.16 version. The set of supported APIs may be expanded over time. Also future releases may change the baseline version of NumPy API being supported. A list of some systematic differences with NumPy are listed later in the "Differences with NumPy" section. ## Getting Started Please also see [TensorFlow NumPy Guide]( https://www.tensorflow.org/guide/tf_numpy). In the code snippets below, we will assume that `tf.experimental.numpy` is imported as `tnp` and NumPy is imported as `np` ```python print(tnp.ones([2,1]) + tnp.ones([1, 2])) ``` ## Types The module provides an `ndarray` class which wraps an immutable `tf.Tensor`. Additional functions are provided which accept array-like objects. Here array-like objects includes `ndarrays` as defined by this module, as well as `tf.Tensor`, in addition to types accepted by NumPy. A subset of NumPy dtypes are supported. Type promotion follows NumPy semantics. ```python print(tnp.ones([1, 2], dtype=tnp.int16) + tnp.ones([2, 1], dtype=tnp.uint8)) ``` ## Array Interface The `ndarray` class implements the `__array__` interface. This should allow these objects to be passed into contexts that expect a NumPy or array-like object (e.g. matplotlib). ```python np.sum(tnp.ones([1, 2]) + np.ones([2, 1])) ``` ## TF Interoperability The TF-NumPy API calls can be interleaved with TensorFlow calls without incurring Tensor data copies. This is true even if the `ndarray` or `tf.Tensor` is placed on a non-CPU device. In general, the expected behavior should be on par with that of code involving `tf.Tensor` and running stateless TensorFlow functions on them. ```python tnp.sum(tnp.ones([1, 2]) + tf.ones([2, 1])) ``` Note that the `__array_priority__` is currently chosen to be lower than `tf.Tensor`. Hence the `+` operator above returns a `tf.Tensor`. Additional examples of interopability include: * using `with tf.GradientTape()` scope to compute gradients through the TF-NumPy API calls. * using `tf.distribution.Strategy` scope for distributed execution * using `tf.vectorized_map()` for speeding up code using auto-vectorization ## Device Support Given that `ndarray` and functions wrap TensorFlow constructs, the code will have GPU and TPU support on par with TensorFlow. Device placement can be controlled by using `with tf.device` scopes. Note that these devices could be local or remote. ```python with tf.device("GPU:0"): x = tnp.ones([1, 2]) print(tf.convert_to_tensor(x).device) ``` ## Graph and Eager Modes Eager mode execution should typically match NumPy semantics of executing op-by-op. However the same code can be executed in graph mode, by putting it inside a `tf.function`. The function body can contain NumPy code, and the inputs can be `ndarray` as well. ```python @tf.function def f(x, y): return tnp.sum(x + y) f(tnp.ones([1, 2]), tf.ones([2, 1])) ``` Python control flow based on `ndarray` values will be translated by [autograph](https://www.tensorflow.org/code/tensorflow/python/autograph/g3doc/reference/index.md) into `tf.cond` and `tf.while_loop` constructs. The code can be XLA compiled for further optimizations. However, note that graph mode execution can change behavior of certain operations since symbolic execution may not have information that is computed during runtime. Some differences are: * Shapes can be incomplete or unknown in graph mode. This means that `ndarray.shape`, `ndarray.size` and `ndarray.ndim` can return `ndarray` objects instead of returning integer (or tuple of integer) values. * `__len__`, `__iter__` and `__index__` properties of `ndarray` may similarly not be supported in graph mode. Code using these may need to change to explicit shape operations or control flow constructs. * Also note the [autograph limitations]( https://github.com/tensorflow/tensorflow/blob/master/tensorflow/python/autograph/g3doc/reference/limitations.md). ## Mutation and Variables `ndarrays` currently wrap immutable `tf.Tensor`. Hence mutation operations like slice assigns are not supported. This may change in the future. Note however that one can directly construct a `tf.Variable` and use that with the TF-NumPy APIs. ```python tf_var = tf.Variable(2.0) tf_var.assign_add(tnp.square(tf_var)) ``` ## Differences with NumPy Here is a non-exhaustive list of differences: * Not all dtypes are currently supported. e.g. `np.float96`, `np.float128`. `np.object`, `np.str`, `np.recarray` types are not supported. * `ndarray` storage is in C order only. Fortran order, views, `stride_tricks` are not supported. * Only a subset of functions and modules are supported. This set will be expanded over time. For supported functions, some arguments or argument values may not be supported. This differences are generally provide in the function comments. Full `ufunc` support is also not provided. * Buffer mutation is currently not supported. `ndarrays` wrap immutable tensors. This means that output buffer arguments (e..g `out` in ufuncs) are not supported * NumPy C API is not supported. NumPy's Cython and Swig integration are not supported. """ # TODO(wangpeng): Append `np_export`ed symbols to the comments above. # pylint: disable=g-direct-tensorflow-import from __future__ import absolute_import from __future__ import division from __future__ import print_function from tensorflow.python.ops.array_ops import newaxis from tensorflow.python.ops.numpy_ops import np_random as random from tensorflow.python.ops.numpy_ops import np_utils # pylint: disable=wildcard-import from tensorflow.python.ops.numpy_ops.np_array_ops import * from tensorflow.python.ops.numpy_ops.np_arrays import ndarray from tensorflow.python.ops.numpy_ops.np_dtypes import * from tensorflow.python.ops.numpy_ops.np_math_ops import * # pylint: enable=wildcard-import from tensorflow.python.ops.numpy_ops.np_utils import finfo from tensorflow.python.ops.numpy_ops.np_utils import promote_types from tensorflow.python.ops.numpy_ops.np_utils import result_type # pylint: disable=redefined-builtin,undefined-variable @np_utils.np_doc("max", link=np_utils.AliasOf("maximum")) def max(a, axis=None, keepdims=None): return amax(a, axis=axis, keepdims=keepdims) @np_utils.np_doc("min", link=np_utils.AliasOf("minimum")) def min(a, axis=None, keepdims=None): return amin(a, axis=axis, keepdims=keepdims) @np_utils.np_doc("round", link=np_utils.AliasOf("around")) def round(a, decimals=0): return around(a, decimals=decimals) # pylint: enable=redefined-builtin,undefined-variable