Source code for mars.tensor.arithmetic.arccosh

#!/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.
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import numpy as np

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

class TensorArccosh(TensorUnaryOp):
    _op_type_ = OperandDef.ARCCOSH
    _func_name = "arccosh"

[docs]@infer_dtype(np.arccosh) def arccosh(x, out=None, where=None, **kwargs): """ Inverse hyperbolic cosine, element-wise. 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 ------- arccosh : Tensor Array of the same shape as `x`. See Also -------- cosh, arcsinh, sinh, arctanh, tanh Notes ----- `arccosh` is a multivalued function: for each `x` there are infinitely many numbers `z` such that `cosh(z) = x`. The convention is to return the `z` whose imaginary part lies in `[-pi, pi]` and the real part in ``[0, inf]``. For real-valued input data types, `arccosh` always returns real output. For each value that cannot be expressed as a real number or infinity, it yields ``nan`` and sets the `invalid` floating point error flag. For complex-valued input, `arccosh` is a complex analytical function that has a branch cut `[-inf, 1]` and is continuous from above on it. References ---------- .. [1] M. Abramowitz and I.A. Stegun, "Handbook of Mathematical Functions", 10th printing, 1964, pp. 86. .. [2] Wikipedia, "Inverse hyperbolic function", Examples -------- >>> import mars.tensor as mt >>> mt.arccosh([mt.e, 10.0]).execute() array([ 1.65745445, 2.99322285]) >>> mt.arccosh(1).execute() 0.0 """ op = TensorArccosh(**kwargs) return op(x, out=out, where=where)