Hi, Lisa Maletzki schrieb:

I have a smallish problem with the method mentioned above (matrix::solve(..)). I have two nxn numeric matrices A and b (from the equation Ax=b) and of course want the matrix x in the end but I keep on getting the error that the first argument must be a matrix of symbols. Now my question how can I do that? I tried it with ex symbolic_matrix(..) but I couldn't get it to work since it is of the type ex and not matrix.

take the following example as a guide: matrix A(2,2); A = 1, 2, 3, 4; symbol x1("x1"), x2("x2"); matrix x(2,1); x = x1, x2; matrix b(2,1); b = 5, 6; cout << A.solve(x, b) << endl; As the manual warns, you will get an exception thrown if the system is overdetermined. A more robust version is shown in the following example using no matrices: symbol x1("x1"), x2("x2"); lst equations; equations.append(1*x1 + 2*x2 == 5); equations.append(3*x1 + 4*x2 == 6); cout << lsolve(equations, lst(x1,x2)) << endl; Regards, Jens