Notes).

    Parameters
    ----------
    a, b : array_like
        Input arrays 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 array.

    Returns
    -------
    y : array_like
        Returns a boolean array 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
    math.isclose

    Notes
    -----
    .. versionadded:: 1.7.0

    For finite values, isclose uses the following equation to test whether
    two floating point values are equivalent.

     absolute(`a` - `b`) <= (`atol` + `rtol` * absolute(`b`))

    Unlike the built-in `math.isclose`, the above equation is not symmetric
    in `a` and `b` -- it assumes `b` is the reference value -- so that
    `isclose(a, b)` might be different from `isclose(b, a)`. Furthermore,
    the default value of atol is not zero, and is used to determine what
    small values should be considered close to zero. The default value is
    appropriate for expected values of order unity: if the expected values
    are significantly smaller than one, it can result in false positives.
    `atol` should be carefully selected for the use case at hand. A zero value
    for `atol` will result in `False` if either `a` or `b` is zero.

    `isclose` is not defined for non-numeric data types.
    `bool` is considered a numeric data-type for this purpose.

    Examples
    --------
    >>> np.isclose([1e10,1e-7], [1.00001e10,1e-8])
    array([ True, False])
    >>> np.isclose([1e10,1e-8], [1.00001e10,1e-9])
    array([ True, True])
    >>> np.isclose([1e10,1e-8], [1.0001e10,1e-9])
    array([False,  True])
    >>> np.isclose([1.0, np.nan], [1.0, np.nan])
    array([ True, False])
    >>> np.isclose([1.0, np.nan], [1.0, np.nan], equal_nan=True)
    array([ True, True])
    >>> np.isclose([1e-8, 1e-7], [0.0, 0.0])
    array([ True, False])
    >>> np.isclose([1e-100, 1e-7], [0.0, 0.0], atol=0.0)
    array([False, False])
    >>> np.isclose([1e-10, 1e-10], [1e-20, 0.0])
    array([ True,  True])
    >>> np.isclose([1e-10, 1e-10], [1e-20, 0.999999e-10], atol=0.0)
    array([False,  True])
    c