def min_max(x,axis=None):
    """
    return min_max standalization
           x = (x-x.min)/(x.max-x.min)
    min=0 max=1

    Parameters
    -------------------
    x : numpy.ndarray(x,y)
    axis :int 0 #caliculate each col
              1 #           each row

    Returns
    --------------------
    result : np.ndarray(x,y)
    """
    xmin =x.min(axis=axis,keepdims=True)
    xmax =x.max(axis=axis,keepdims=True)
    result = (x-xmin)/(xmax-xmin)
    return result