matrix multiplication broken

Brian Gough bjg@network-theory.co.uk
Wed Feb 16 11:23:00 GMT 2000


Thanks for the bug report! I have incorporated the tests, which are
very useful. I have fixed the multiply code in a different way, as
there was also a matrix size/physical dimension issue involved -- it
should all be working now anyway.

regards
Brian Gough

Paul Walmsley writes:
 > 
 > I've recently downloaded and started using the gsl library (primarily with
 > C++ wrappers for matrix classes) but I've found that the generalised
 > multiply operation gsl_la_matmult_mod_impl() (in multiply.c)  is broken.  
 > It works fine for NxN matrices but not MxN.  
 > 
 > I've attached a patch for this. Many apologies: it isn't very elegant, and
 > has a separate subroutine for each combination of A*B, A'*B, A*B' and
 > A'*B', and only deals with the case for matrices of doubles.  I've also
 > included a patch to the test_la.c program to test MxN multiplication,
 > which will fail on the original (release 0.5) source.
 > 
 > The GSL is a great resource -- I'm very glad to have come across it.  Keep
 > up the good work.
 > 
 > 
 > Paul Walmsley
 > --------------------------------------------------------------------------
 > Signal Processing Group                                    
 > Cambridge University Engineering Department                
 > pwalmsley@iee.org pjw42@cam.ac.uk  http://www-sigproc.eng.cam.ac.uk/~pjw42


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