Source code for mars.tensor.arithmetic.isclose

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

from ... import opcodes as OperandDef
from ...serialize import Float64Field, BoolField
from ..array_utils import device, as_same_device
from .core import TensorBinOp


class TensorIsclose(TensorBinOp):
    _op_type_ = OperandDef.ISCLOSE

    _rtol = Float64Field('rtol')
    _atol = Float64Field('atol')
    _equal_nan = BoolField('equal_nan')

    def __init__(self, rtol=None, atol=None, equal_nan=None,
                 casting='same_kind', err=None, dtype=None, sparse=False, **kw):
        err = err if err is not None else np.geterr()
        super().__init__(_rtol=rtol, _atol=atol, _equal_nan=equal_nan, _casting=casting,
                         _err=err, _dtype=dtype, _sparse=sparse, **kw)

    @property
    def rtol(self):
        return self._rtol

    @property
    def atol(self):
        return self._atol

    @property
    def equal_nan(self):
        return self._equal_nan

    @classmethod
    def _is_sparse(cls, x1, x2):
        if hasattr(x1, 'issparse') and x1.issparse() and \
                np.isscalar(x2) and not np.isclose(x2, 0):
            return True
        if hasattr(x2, 'issparse') and x2.issparse() and \
                np.isscalar(x1) and not np.isclose(x1, 0):
            return True
        return False

    @classmethod
    def execute(cls, ctx, op):
        inputs, device_id, xp = as_same_device(
            [ctx[c.key] for c in op.inputs], device=op.device, ret_extra=True)

        with device(device_id):
            a = op.lhs if np.isscalar(op.lhs) else inputs[0]
            b = op.rhs if np.isscalar(op.rhs) else inputs[-1]

            ctx[op.outputs[0].key] = xp.isclose(a, b, atol=op.atol, rtol=op.rtol,
                                                equal_nan=op.equal_nan)


[docs]def isclose(a, b, rtol=1e-05, atol=1e-08, equal_nan=False): """ Returns a boolean tensor where two tensors are element-wise equal within a tolerance. The tolerance values are positive, typically very small numbers. The relative difference (`rtol` * abs(`b`)) and the absolute difference `atol` are added together to compare against the absolute difference between `a` and `b`. Parameters ---------- a, b : array_like Input tensors to compare. rtol : float The relative tolerance parameter (see Notes). atol : float The absolute tolerance parameter (see Notes). equal_nan : bool Whether to compare NaN's as equal. If True, NaN's in `a` will be considered equal to NaN's in `b` in the output tensor. Returns ------- y : array_like Returns a boolean tensor of where `a` and `b` are equal within the given tolerance. If both `a` and `b` are scalars, returns a single boolean value. See Also -------- allclose Notes ----- For finite values, isclose uses the following equation to test whether two floating point values are equivalent. absolute(`a` - `b`) <= (`atol` + `rtol` * absolute(`b`)) The above equation is not symmetric in `a` and `b`, so that `isclose(a, b)` might be different from `isclose(b, a)` in some rare cases. Examples -------- >>> import mars.tensor as mt >>> mt.isclose([1e10,1e-7], [1.00001e10,1e-8]).execute() array([True, False]) >>> mt.isclose([1e10,1e-8], [1.00001e10,1e-9]).execute() array([True, True]) >>> mt.isclose([1e10,1e-8], [1.0001e10,1e-9]).execute() array([False, True]) >>> mt.isclose([1.0, mt.nan], [1.0, mt.nan]).execute() array([True, False]) >>> mt.isclose([1.0, mt.nan], [1.0, mt.nan], equal_nan=True).execute() array([True, True]) """ op = TensorIsclose(rtol=rtol, atol=atol, equal_nan=equal_nan, dtype=np.dtype(bool)) return op(a, b)