bernhold@qtp.ufl.edu (David E. Bernholdt) (12/05/90)
About 10 days ago, I sent out a request for information on sparse BLAS-1 implementations. Here is a summary of the response... There is a paper by Dodson, Grimes and Lewis (DGL) describing a set of sparse BLAS-1 routines. The paper and model routines are available from netlib. I understand it will be appearing in the ACM Transactions on Mathematical Software as well. This is the most "popular" such definition of which I am aware. These routines have been implemented in the NAG Mark 14 Fortran library. The IBM ESSL library implements 10 of the routines -- the single and double precision, but not the comple or double complex. Cray's SCILIB has several sparse BLAS-1 type operations. They have different names and arguments from the Dodson, Grimes and Lewis definitions. I have heard two different rumors about Cray implementing the DGL definitions: From one source that they have been implemented, but from another that they are not scheduled for release to the public. In any event, it looks like the DGL proposal is begining to catch on with the vendors. As I suspected, there is little concensus on what "sparse blas" should be. I think it is fairly clear for BLAS-1, but much less so for higher levels. I get the feeling that most people working with sparse problems are "rolling their own" basic routines. Some people expressed doubt that sparse versions of the higher-level BLAS would ever catch on. That being said, I should note that the paper "Are there iterative BLAS?" by Oppe and Kincaid includes a slightly different approach sparse level-1 BLAS (as part of what they call "iterative BLAS") -- more general and somewhat more flexible than the DGL proposal, but with basically the same operations available. The Oppe & Kincaid paper is the only other proposal which received any mention. They are aiming at a fundamental set of routines for the development of sparse iterative solvers, so they include numerous routines aimed at different common storage/problem structures. Thanks to all who replied. I hope this summary is useful. -- David Bernholdt bernhold@qtp.ufl.edu Quantum Theory Project bernhold@ufpine.bitnet University of Florida Gainesville, FL 32611 904/392 6365