projection.py 文件源码

def orthoProjection(X, n):

    # check if X is a subspace of the original space
    if rank(X) < n:
        P = X.dot(la.inv(X.conjugate().T.dot(X))).dot(X.conjugate().T)

        # return: orthogonal projection onto subspace X, orthogonal projection X's orthogonal complement subspace
        return P, np.eye(P.shape[0]) - P
    else:
        raise Exception('not a subspace')

# projection transformation from original space onto its subspace X along its completement Y