尝试使用 math.net 计算非方阵的伪逆

Question

I am trying to use math.net library to compute the pseudoinverse of a matrix, but so far I have gotten an error telling me when I try to use this below code :

   B = A.Inverse();

that the matrix must be square. However here

http://iridium.mathdotnet.com/api/mathnet.numerics.linearalgebra/matrix.htm#Inverse

it is said that the inverse method calculates the pseudoinverse. This is also said here:

https://mathnetnumerics.codeplex.com/discussions/251084

Am I using the wrong version of the library? So far I have been using Math.Net.Numerics3.4.0 , I added a reference to ac# project to MathNetNumerics.dll found in the folder Net4.0

Any help will be greatly appreciated.

Answer 1

According to this documentation :

inverse(A) if A is square, pseudoinverse otherwise.

To me this looks like the Matrix.Inverse() method will fail if given a non-invertible (but square) matrix. This behavior may be intentional. Sometimes a non-invertible matrix represents a serious error that you want to be alerted about. Also, if you know that the matrix should always be invertible when square, Inverse MAY be slightly faster than PseudoInverse.