__init__.py 文件源码

def is_mirror_image(X, Y):
    """
    Check if two configurations X and Y are mirror images
    (i.e. their optimal superposition involves a reflection).

    @param X: n x 3 input vector
    @type X: numpy array
    @param Y: n x 3 input vector
    @type Y: numpy array

    @rtype: bool
    """
    from numpy.linalg import det, svd

    ## center configurations

    X = X - numpy.mean(X, 0)
    Y = Y - numpy.mean(Y, 0)

    ## SVD of correlation matrix

    V, L, U = svd(numpy.dot(numpy.transpose(X), Y))             #@UnusedVariable

    R = numpy.dot(V, U)

    return det(R) < 0