視頻里給出了 julia, octave, 北太天元 做矩陣構(gòu)造，求逆矩陣，求特征值， 求LDL分解 四種基本操作， 再補上python 的做這四種基本操作的結(jié)果:

>>> import numpy as np

>>> A = np.array( [ [ 1 , 2 ], [3 , 4] ] )

>>> numpy.linalg.inv(A)

array([[-2. ,?1. ],

??????[ 1.5, -0.5]])

>>> numpy.linalg.eig(A)

(array([-0.37228132,?5.37228132]), array([[-0.82456484, -0.41597356],

??????[ 0.56576746, -0.90937671]]))

>>> numpy.linalg.ldl(A)

Traceback (most recent call last):

?File "<stdin>", line 1, in <module>

AttributeError: 'module' object has no attribute 'ldl'