eigen/doc/examples/class_Block.cpp
Benoit Jacob 86220784b6 part 2 of the reorganization. Benefits/changes:
1) Eigen2 co-installable with Eigen1 without conflict, without affecting programs including either.
2) #include<Eigen/Core> without the .h without conflict with the Core/ directory
3) Uniformize coding style of the CMakeLists.
2007-12-28 16:20:00 +00:00

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#include <Eigen/Core>
USING_PART_OF_NAMESPACE_EIGEN
using namespace std;
template<typename Scalar, typename Derived>
Eigen::Block<Derived, 2, 2>
topLeft2x2Corner(MatrixBase<Scalar, Derived>& m)
{
return Eigen::Block<Derived, 2, 2>(m.ref(), 0, 0);
}
template<typename Scalar, typename Derived>
const Eigen::Block<Derived, 2, 2>
topLeft2x2Corner(const MatrixBase<Scalar, Derived>& m)
{
return Eigen::Block<Derived, 2, 2>(m.ref(), 0, 0);
}
int main(int, char**)
{
Matrix3d m = Matrix3d::identity();
cout << topLeft2x2Corner(4*m) << endl; // calls the const version
topLeft2x2Corner(m) *= 2; // calls the non-const version
cout << "Now the matrix m is:" << endl << m << endl;
return 0;
}