矩阵上的Scipy线性化器

Question

我有一个线性函数A，它的输入和输出是(m,n)numpy数组。我想用CG或GMRES来解决一个系统A(x) = b。有没有什么方法可以定义scipyLinearOperator，而不改变函数A中的输入和输出？在

示例：

import numpy as np
import scipy.sparse.linalg as linalg

a = np.array( [ [1,2] , [3,4] ] )
def A(v):
    return a * v

# I want to do this but this fails. Any other
# solution that doesn't involve reshaping?
lin_op = linalg.LinearOperator( ((2,2),(2,2)), matvec=A )