Source code for mars.tensor.arithmetic.isnan

#!/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 inject_dtype
from .core import TensorUnaryOp
from .utils import arithmetic_operand

class TensorIsNan(TensorUnaryOp):
    _op_type_ = OperandDef.ISNAN
    _func_name = "isnan"

[docs]@inject_dtype(np.bool_) def isnan(x, out=None, where=None, **kwargs): """ Test element-wise for NaN and return result as a boolean tensor. 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 or bool For scalar input, the result is a new boolean with value True if the input is NaN; otherwise the value is False. For array input, the result is a boolean tensor of the same dimensions as the input and the values are True if the corresponding element of the input is NaN; otherwise the values are False. See Also -------- isinf, isneginf, isposinf, isfinite, isnat Notes ----- Mars uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754). This means that Not a Number is not equivalent to infinity. Examples -------- >>> import mars.tensor as mt >>> mt.isnan(mt.nan).execute() True >>> mt.isnan(mt.inf).execute() False >>> mt.isnan([mt.log(-1.).execute(),1.,mt.log(0).execute()]).execute() array([ True, False, False]) """ op = TensorIsNan(**kwargs) return op(x, out=out, where=where)