Hi Marco, On Tue, Jun 28, 2005 at 04:05:46PM -0300, mdias@ift.unesp.br wrote:

I am tryng to solve a linear system with lsove(), with many variables being zero, so lsolve() tell that is indeterminate, but some of these entries are of interest. So, I am looking for matrix::solve and construct a matrix to solve this. Somebody have a piece of code how to make a linear system a matrix to matrix::solve ?

I don't completely understand your question concerning these "entries of interest", but maybe you want to have something like this: #include <iostream> using namespace std; #include <ginac/ginac.h> using namespace GiNaC; int main() { symbol f1("f1"), f2("f2"); symbol A("A"), B("B"); matrix M(2, 2, lst(f1, f1*f2, 0, f2)); matrix x(2, 1, lst(A, B)); matrix b(2, 1, lst(5, 10)); // M x = b matrix result = M.solve(x, b); cout << result << endl; return 0; } Just a small example that can easily be adapted to bigger systems. Regards, Jens

On Tue, 28 Jun 2005 mdias@ift.unesp.br wrote:

I am tryng to solve a linear system with lsove(), with many variables being zero, so lsolve() tell that is indeterminate, but some of these entries are of interest. So, I am looking for matrix::solve and construct a matrix to solve this. Somebody have a piece of code how to make a linear system a matrix to matrix::solve ?

Please have a close look at the code in check/exam_lsolve.cpp and check/check_lsolve.cpp. It contains several regression tests for lsolve including over- and underdetermined linear systems. Regards -richy. -- Richard B. Kreckel <http://www.ginac.de/~kreckel/>