Source code for mars.tensor.arithmetic.cosh

#!/usr/bin/env python
# -*- coding: utf-8 -*-
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#      http://www.apache.org/licenses/LICENSE-2.0
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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


@arithmetic_operand(sparse_mode='unary')
class TensorCosh(TensorUnaryOp):
    _op_type_ = OperandDef.COSH
    _func_name = 'cosh'


[docs]@infer_dtype(np.cosh) def cosh(x, out=None, where=None, **kwargs): """ Hyperbolic cosine, element-wise. Equivalent to ``1/2 * (mt.exp(x) + mt.exp(-x))`` and ``mt.cos(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 ------- out : Tensor Output array of same shape as `x`. Examples -------- >>> import mars.tensor as mt >>> mt.cosh(0).execute() 1.0 The hyperbolic cosine describes the shape of a hanging cable: >>> import matplotlib.pyplot as plt >>> x = mt.linspace(-4, 4, 1000) >>> plt.plot(x.execute(), mt.cosh(x).execute()) >>> plt.show() """ op = TensorCosh(**kwargs) return op(x, out=out, where=where)