python——argwhere（）函数

函数功能： 返回数组里面大于某个设定值的数对应的索引

def argwhere(a):
    """
    Find the indices of array elements that are non-zero, grouped by element.

    Parameters
    ----------
    a : array_like
        Input data.

    Returns
    -------
    index_array : (N, a.ndim) ndarray
        Indices of elements that are non-zero. Indices are grouped by element.
        This array will have shape ``(N, a.ndim)`` where ``N`` is the number of
        non-zero items.

    See Also
    --------
    where, nonzero

    Notes
    -----
    ``np.argwhere(a)`` is almost the same as ``np.transpose(np.nonzero(a))``,
    but produces a result of the correct shape for a 0D array.

    The output of ``argwhere`` is not suitable for indexing arrays.
    For this purpose use ``nonzero(a)`` instead.

    """
    # nonzero does not behave well on 0d, so promote to 1d
    if np.ndim(a) == 0:
        a = shape_base.atleast_1d(a)
        # then remove the added dimension
        return argwhere(a)[:,:0]
    return transpose(nonzero(a))

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