On 11/14/11 15:53, pmamales@nyc.rr.com wrote:
Hi Larry,
Ah! I should have read closer. BTW, since, based on our past emails, you're interested in linear equation solvers for tridiagonal systems, maybe you could let me know how you're solving tridiagonal systems with ublas or lapack. I'd appreciate it.
Well, blas does not provide with any, and lapack providees with expensive ones (w/pivoting and all that, and only saves on the memory footprint, and multiplies with 0's until kingdom comes ;-)). You are much better off googling Thomas Algorithm and implementing it on your own (does not take much at all).
Done: http://svn.boost.org/svn/boost/sandbox/variadic_templates/sandbox/stepper/bo...
I would advise you have the lapack ones avail too, for the "nasty" problems. Look in LAPACk for *gtsv, *gtsvx, *ptsv, *ptsvx where * stands for s,d,c or z for float, double, complex<float> and complex<double> respectively. You will have to do a little wrapping, but who doesn't ;))
Did the *gtsv in the attached. To get it to link, had to add: -llapack -lblas -lgfortran options to link command. The in source comments indicate that lapack knows the matrix is banded; hence, I'm a bit surprised at your observation that it: multiplies with 0's until kingdom comes ;-)). Any idea why? [snip] Thanks for the help Petros. -regards, Larry