Search found 6 matches

by blattms
Tue Feb 19, 2019 9:41 am
Forum: User discussion
Topic: [bug] lobpcg does not return valid success/error code in solver_par.info
Replies: 0
Views: 425

[bug] lobpcg does not return valid success/error code in solver_par.info

The problem is that the info object created inside the routine is passed to the function magma_dsyevd_gpu as the last step where the info object is used. Then this info object is used to report success and/or error of the lobpcg method in solver_par.info. The problem is that in my case magma_dsyevd_...
by blattms
Tue Feb 19, 2019 9:24 am
Forum: User discussion
Topic: calculate k smallest eigenvalues using LOBPCG
Replies: 3
Views: 760

Re: calculate k smallest eigenvalues using LOBPCG

According to viewtopic.php?f=2&t=1266&p=3677&hilit=l ... 483a#p3677 it calculates the smallest eigenvalues. The thread also explains how to trick it into computing the largest ones.
by blattms
Thu Oct 18, 2018 10:51 am
Forum: User discussion
Topic: Matrix formats for lobpcg
Replies: 4
Views: 1213

Re: Matrix formats for lobpcg

Well, if I only request one eigenvalue, then the results seem similar. But this seems to be the only case. In all others lobpcg with SELLP thinks the initial residual is already small enough. Tested with up to 9 Eigen values.
by blattms
Thu Oct 18, 2018 10:30 am
Forum: User discussion
Topic: Matrix formats for lobpcg
Replies: 4
Views: 1213

Re: Matrix formats for lobpcg

Ok, I did move to using SELLP, but it is not working yet. I am getting an error message "error: number of vectors has to be multiple of 2" in the sparse matrix vector multiplication. No sure what this is due to. So I tested lobpcg using testing_dsolver. To make it run through without error mesage I ...
by blattms
Tue Oct 16, 2018 1:17 pm
Forum: User discussion
Topic: Matrix formats for lobpcg
Replies: 4
Views: 1213

Re: Matrix formats for lobpcg

Thanks for your answer Stan. Unfortunately that would mean patching Magma, as I want to use the lobcpg solver for an ELLP matrix (and not do sparse matrix-vector product directly. They are just where it breaks..). I also assume that Magma makes use on BLAS level 3 operations (dense matriy-matrix mul...
by blattms
Wed Oct 10, 2018 3:56 am
Forum: User discussion
Topic: Matrix formats for lobpcg
Replies: 4
Views: 1213

Matrix formats for lobpcg

Hi, I wanted to use lobpcg to compute some eigenvalues and eigenvectors. Assuming that all matrix types should be supported I chose Magma_ELL as sparse matrix format. Unfortunately, due to the implementation of magma_d_spmv in magma_d_blaswrapper.cpp this format is only supported for real vectors (n...