>>> from numpy import *
>>> rMat1 = mat(random.rand(4,4))
>>> rMat1
matrix([[ 0.64942483, 0.13354212, 0.73462188, 0.84064478],
[ 0.98905725, 0.47277942, 0.46831185, 0.04350675],
[ 0.1914044 , 0.85404567, 0.52689656, 0.38911737],
[ 0.50723587, 0.33690424, 0.96063439, 0.42176084]])
>>> rMat2 = rMat1.I
>>> rMat2
matrix([[ 0.48364538, 1.12727011, -0.43000817, -0.68354892],
[-0.31685954, 0.26538305, 1.31309351, -0.6072805 ],
[-0.85113497, -0.46638126, -0.46684178, 2.17528291],
[ 1.61005598, -0.50544909, 0.53156445, -1.27640031]])
>>> rMat1*rMat2
matrix([[ 1.00000000e+00, 1.11022302e-16, -5.55111512e-17,
0.00000000e+00],
[ 2.77555756e-17, 1.00000000e+00, -1.04083409e-17,
6.93889390e-18],
[ 1.11022302e-16, 2.77555756e-17, 1.00000000e+00,
-1.11022302e-16],
[ 0.00000000e+00, 8.32667268e-17, -5.55111512e-17,
1.00000000e+00]])
>>> rMat1*rMat2 - eye(4)
matrix([[ 0.00000000e+00, 1.11022302e-16, -5.55111512e-17,
0.00000000e+00],
[ 2.77555756e-17, 0.00000000e+00, -1.04083409e-17,
6.93889390e-18],
[ 1.11022302e-16, 2.77555756e-17, 0.00000000e+00,
-1.11022302e-16],
[ 0.00000000e+00, 8.32667268e-17, -5.55111512e-17,
0.00000000e+00]])
.I 操作符实现了矩阵求逆的运算，eye（4）产生4×4的单位矩阵，相减可以得到误差。
