need a little IMSL help, harwell-boeing sparse matrix features

[Brian_Murphy]

Can I get help with use of the s_hbc_sparse features of IMSL on this forum?  Or should I go to roguewave forums?

I want to know if it is possible to do an LU factor, followed by many linear equation solves, with a sparse matrix using the s_hbc_sparse derived type and overloaded operators.

Thanks,

Brian in Austin, Texas

[Steven_L_Intel1]

There are some experienced IMSL users here, but I would recommend asking in the Rogue Wave forums.

[Brian_Murphy]

I posted at Roguewave last week.  So far no replies.  I gotta believe that if they call it SuperLU, it ought to be able to do what I want.  Isn't that what LU factoring is all about?  I suppose I'll have to make test program and take a stab at it.  I'll just be guessing as to how to get the LU to be saved.  I don't see anything in the IMSL documentation about that.

Brian

[Steven_L_Intel1]

Let me forward your question to my counterparts at RW and see what they say.

[Steven_L_Intel1]

Ok, got an answer:

Yes, he is correct. For the sparse operator using SuperLU, the LU  factorization is done on the first “call” to .ix. and saved for any subsequent calls for the same s_hbc_sparse definition.

[Brian_Murphy]

Thanks, Steve.  I am preparing code right now that will try this.  It's in the iteration loop of an Arnoldi eigensolver.

Cheers,

Brian