[My apologies for the repost. I have been alerted to the fact that the headers on my last post were strange.]
Good points, Mike. I completely agree that it is better to work from FORTRAN sources than a FORTRAN to C version, and to directly link from J. I am starting from the cygwin distribution: these are Windows DLLs compiled from FORTRAN, they are freely available, and they are being actively maintained. See http://www.mail-archive.com/[email protected]/msg01455.html If this fails, the LAPACK site has precompiled versions using several different FORTRAN compilers. There is also GNU g77, which is not just a FORTRAN-to-C front end. As I read more, it becomes clearer that having a locally-optimized BLAS is important. I hope to figure out how to do this, too. Best wishes, John Mike Day wrote: > I certainly didn't mean to scoff at Fortran - it was my first programming > language and I still know it much better than C. I _was_ trying to say > that > it might be more sensible, as you're (JR) doing, to link J directly - or > almost directly - to a fortran-compiled library rather than a > c-compilation > of a translation from fortran to c, which might be expected to suffer from > "loss in translation" and inapplicability of the hand-coded fortran > optimisation to a c binary. > > Later postings discuss Fortran's column-major ordering. With a bit of > care, > it wouldn't necessarily matter. For example, in dgeev, which had so much > discussion recently, the current dgeev_jlapack_ verb transposes the input > matrix to satisfy Fortran's column-major requirement. But if you don't > bother to transpose it, the answers are still usable; you can just swap > the left & right-hand eigenvectors, premultiply instead of postmultiply, > etc etc. Perhaps there are some rank-3 or greater arrays somewhere where > all this gets too confusing. > > The matlisp library whic I mentioned yesterday includes many fortran > routines not in LAPACK or BLAS, so the new number of LAPACK entries is > about 640 rather than the 800+ I claimed earlier. > > Mike > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
