Hello Everybody,

I want to solve the system Ax = b using any method possible. I already know C++ but I don't have a clue using Eigen. I did search the forum and also looked for tutorials online.
If someone can show me the methods (function calls) needed to solve a matrix thats all I need to know. I would also like to use the fastest method if possible. I know Gaussian elimination but I think there are other ones out there. I'm trying to use this to solve the heat equation using the finite element method.

thanks,

Andrew

If you're doing FEM then I guess you're looking for solving large and sparse problems. Then you can start by looking at this example:

http://eigen.tuxfamily.org/dox-devel/gr ... tml#title1

that solve the Laplace equation using finite differences. Then read this page for the details: http://eigen.tuxfamily.org/dox-devel/gr ... stems.html.

ggael wrote:If you're doing FEM then I guess you're looking for solving large and sparse problems. Then you can start by looking at this example:

I'm not sure if its sparse. Basically each cell has 6 faces so there are 6 unknowns (in 3d). The matrices are something like
edit:
a11x + a12y + a13z + a14i + a15j + a16k = Constant1
a21x + a22y + a23z + a24i + a25j + a26k = Constant2

and all the variables x,y,z,i,j,k are used, wouldn't that be dense?