As I understand it, HP's Advantage Pac matrix functions originated from the CCD module. The MSYS program solves a linear system of eqns by LU decomposition, whereas the CCD manual lists the source for a program called ABIN that performs gauss elimination, using R-PR and R-QR (on the CCD module). I could not find these in the Advantage Pac, and was wondering why these two functions didn't make the cut?
Edited: 7 Mar 2012, 1:44 p.m.
With the exception you point out, the Advantage implementation is a superset that built on the CCD functions and added a few other ones, like MSYS, MDET and MINV. There was no need for the FOCAL programs listed on the CCD manual, much slower and with many other dependencies.
I guess the dropped functions didn't make it because there were deemed not needed once the high-level functions were added. I looked at the MCODE and tried a couple of quick and dirty patches to see if the code was still there, but they seem to be gone for good.
Expanding on this, If I wanted to compare a solution using gauss elimination versus LU-decomposition, what would you suggest? Or an iterative method, such as Gauss-Seidel, for larger systems?
Edited: 7 Mar 2012, 4:14 p.m.