Hello,

I am trying to use CG to solve A*X=B. Seems that CG is only available in the development branch right now?

Anyway, I have a strange compile error.

Code: Select all

#include <Eigen/SparseCore>
#include <Eigen/Dense>
#include <Eigen/IterativeLinearSolvers>

int n = 10000;
VectorXd x(n), b(n);
SparseMatrix<double> A(n,n);
// fill A and b
ConjugateGradient<SparseMatrix<double> > cg;
cg(A);
x = cg.solve(b);



It is directly copied from the document. However, there is a compile error here：

Error: no match for call to ‘(Eigen::ConjugateGradient<Eigen::SparseMatrix<double, 0, int>, 1, Eigen::DiagonalPreconditioner<double> >) (Eigen::SparseMatrix<double, 0, int>&)’


Am I missing something?

I figured it out, it should be

cg.solver(A);

pidanchen wrote:Hello,

I am trying to use CG to solve A*X=B. Seems that CG is only available in the development branch right now?

Anyway, I have a strange compile error.

Code: Select all

#include <Eigen/SparseCore>
#include <Eigen/Dense>
#include <Eigen/IterativeLinearSolvers>

int n = 10000;
VectorXd x(n), b(n);
SparseMatrix<double> A(n,n);
// fill A and b
ConjugateGradient<SparseMatrix<double> > cg;
cg(A);
x = cg.solve(b);



It is directly copied from the document. However, there is a compile error here：

Error: no match for call to ‘(Eigen::ConjugateGradient<Eigen::SparseMatrix<double, 0, int>, 1, Eigen::DiagonalPreconditioner<double> >) (Eigen::SparseMatrix<double, 0, int>&)’


Am I missing something?

hm, no, it's rather:

cg.compute(A);

There is no such "solver" function.