Good day

I am quite new to programming and is trying to get Eigen to work
on Microsoft visual studio 2010.

I created a Win32 Application Console,
Properties->General->Character set->not set
added c:\eigen to VC++ Directories -> Include Directories,
added #include "Eigen/Core"

Program:
#include "stdafx.h"
#include "Eigen/Core"

int _tmain(int argc, _TCHAR* argv[])
{
Matrix3f a;
a << 1,2,3,4,5,6,7,8,9;
return 0;
}

then when compiling I receive error : Matrix3f undeclared identifier.

What am I doing wrong, can someone please help?

O, I extracted the new eigen so that c:\eigen\Eigen\Core

Matrix3f (and similar type identifiers) are declared in the Eigen namespace, so you have to add either "using Eigen::Matrix3f;" or "using namespace Eigen;" to your program.

Have a look at the example programs on http://eigen.tuxfamily.org/dox-devel/Ge ... arted.html .

Thank you, I feel like an idiot now...