utils.py 文件源码

def chi2(exp, obs):
    """
        Compute CHI^2 statistics of non-zero expected elements
    """
    zero = tf.constant(0, dtype=tf.float32)
    mask = tf.not_equal(exp, zero)

    def masking(tensor, mask):
        return tf.boolean_mask(tensor, mask)

    stat = tf.reduce_sum(
        tf.div(
            tf.pow(
                tf.subtract(masking(obs, mask), masking(exp, mask)),
                2),
            masking(exp, mask)),
        name="chi2_statistics")

    return stat