#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright 1999-2020 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
#
# 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
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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 TensorCbrt(TensorUnaryOp):
_op_type_ = OperandDef.CBRT
_func_name = 'cbrt'
@infer_dtype(np.cbrt)
def cbrt(x, out=None, where=None, **kwargs):
"""
Return the cube-root of an tensor, element-wise.
Parameters
----------
x : array_like
The values whose cube-roots are required.
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
An tensor of the same shape as `x`, containing the cube
cube-root of each element in `x`.
If `out` was provided, `y` is a reference to it.
Examples
--------
>>> import mars.tensor as mt
>>> mt.cbrt([1,8,27]).execute()
array([ 1., 2., 3.])
"""
op = TensorCbrt(**kwargs)
return op(x, out=out, where=where)
