brsa.py 文件源码

def _zscore(a):
    """ Calculating z-score of data on the first axis.
        If the numbers in any column are all equal, scipy.stats.zscore
        will return NaN for this column. We shall correct them all to
        be zeros.

    Parameters
    ----------
    a: numpy array

    Returns
    -------
    zscore: numpy array
        The z-scores of input "a", with any columns including non-finite
        numbers replaced by all zeros.
    """
    assert a.ndim > 1, 'a must have more than one dimensions'
    zscore = scipy.stats.zscore(a, axis=0)
    zscore[:, np.logical_not(np.all(np.isfinite(zscore), axis=0))] = 0
    return zscore