View Single Post
Old 2020-10-05, 15:06   #4
jasonp
Tribal Bullet
 
jasonp's Avatar
 
Oct 2004

2·29·61 Posts
Default

You figured it out, but yes the block Lanczos algorithm finds the nullspace of A^T*A and not of A, since the algorithm only works for symmetric matrices.To get the answers you need, Gauss elimination of the nullspace vectors you have is necessary.

I remember how great it felt when I managed to get the code running on a real problem, BL is hard to figure out from papers, or even from other people's code.
jasonp is offline   Reply With Quote