On Thu, May 18, 2006 at 11:21:33AM -0500, Linas Vepstas wrote: > On Wed, May 17, 2006 at 02:45:10PM -0600, [EMAIL PROTECTED] wrote: > > > > I have recently needed to compute eigenvalues of unsymmetric > > matrices, > > When I hit ths problem, someone recommended LAPACK, which > I then used happily (routine DGEEV). This mailing list has > seen occasional discusions about how to wrap/merge/whatever > LAPACK routines with gsl (a technical problem is that LAPACK > uses the fortran calling convention, making it ugly in C.)
LAPACK I believe uses the same QR algorithm which I have been implementing, so if I can make it as robust as LAPACK's implementation it should be a far better alternative than linking to fortran code. > > > + f *= FLOAT_RADIX; > > Is this right? isn't there a "DOUBLE_RADIX" ? I don't believe there is any standard define for the radix of the floating point unit. The 'float' and 'double' radixes are always the same of course - it is the base which the FPU uses to represent float/double numbers. I used "FLOAT" to refer to the floating point unit rather than float vs double. As a side note, I noticed there is an underflow issue in the patch I submitted yesterday which shows up for larger matrices 8x8+. I will try to fix this asap. Patrick Alken
