algebraic.py 文件源码

def max_edge(arr, threshold=0.5, axis=1):
    """ Find strongest decreasing edge on each row """
    if axis == 0:
        arr = arr.T
    if np.issubdtype(arr.dtype, np.unsignedinteger):
        arr = arr.astype(np.int)
    derivative = -np.diff(arr)
    index = np.argmax(derivative, axis=1)
    values = np.max(derivative, axis=1)
    r_dev = index + 0.5
    r_dev[values < threshold * values.max()] = np.nan
    return r_dev