Source code for mars.tensor.arithmetic.tanh

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright 1999-2021 Alibaba Group Holding Ltd.
# 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
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# See the License for the specific language governing permissions and
# limitations under the License.

import numpy as np

from ... import opcodes as OperandDef
from ..utils import infer_dtype
from .core import TensorUnaryOp
from .utils import arithmetic_operand

class TensorTanh(TensorUnaryOp):
    _op_type_ = OperandDef.TANH
    _func_name = "tanh"

[docs]@infer_dtype(np.tanh) def tanh(x, out=None, where=None, **kwargs): """ Compute hyperbolic tangent element-wise. Equivalent to ``mt.sinh(x)/np.cosh(x)`` or ``-1j * mt.tan(1j*x)``. Parameters ---------- x : array_like Input tensor. out : Tensor, None, or tuple of Tensor and None, optional A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or `None`, a freshly-allocated tensor is returned. A tuple (possible only as a keyword argument) must have length equal to the number of outputs. where : array_like, optional Values of True indicate to calculate the ufunc at that position, values of False indicate to leave the value in the output alone. **kwargs Returns ------- y : Tensor The corresponding hyperbolic tangent values. Notes ----- If `out` is provided, the function writes the result into it, and returns a reference to `out`. (See Examples) References ---------- .. [1] M. Abramowitz and I. A. Stegun, Handbook of Mathematical Functions. New York, NY: Dover, 1972, pg. 83. .. [2] Wikipedia, "Hyperbolic function", Examples -------- >>> import mars.tensor as mt >>> mt.tanh((0, mt.pi*1j, mt.pi*1j/2)).execute() array([ 0. +0.00000000e+00j, 0. -1.22460635e-16j, 0. +1.63317787e+16j]) >>> # Example of providing the optional output parameter illustrating >>> # that what is returned is a reference to said parameter >>> out1 = mt.zeros(1) >>> out2 = mt.tanh([0.1], out1) >>> out2 is out1 True >>> # Example of ValueError due to provision of shape mis-matched `out` >>> mt.tanh(mt.zeros((3,3)),mt.zeros((2,2))) Traceback (most recent call last): ... ValueError: operands could not be broadcast together with shapes (3,3) (2,2) """ op = TensorTanh(**kwargs) return op(x, out=out, where=where)