eigen/doc/examples/class_Block.cpp
Benoit Jacob fb3438e609 - expand MathFunctions.h to provide more functions, like exp, log...
- add cwiseExp(), cwiseLog()...
   --> for example, doing a gamma-correction on a bitmap image stored as
       an array of floats is a simple matter of:
         Eigen::Map<VectorXf> m = VectorXf::map(bitmap,size);
         m = m.cwisePow(gamma);
- apidoc improvements, reorganization of the \name's
- remove obsolete examples
- remove EIGEN_ALWAYS_INLINE on lazyProduct(), it seems useless.
2008-03-14 10:38:37 +00:00

27 lines
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C++

#include <Eigen/Core>
USING_PART_OF_NAMESPACE_EIGEN
using namespace std;
template<typename Derived>
Eigen::Block<Derived>
topLeftCorner(MatrixBase<Derived>& m, int rows, int cols)
{
return Eigen::Block<Derived>(m.derived(), 0, 0, rows, cols);
}
template<typename Derived>
const Eigen::Block<Derived>
topLeftCorner(const MatrixBase<Derived>& m, int rows, int cols)
{
return Eigen::Block<Derived>(m.derived(), 0, 0, rows, cols);
}
int main(int, char**)
{
Matrix4d m = Matrix4d::identity();
cout << topLeftCorner(4*m, 2, 3) << endl; // calls the const version
topLeftCorner(m, 2, 3) *= 5; // calls the non-const version
cout << "Now the matrix m is:" << endl << m << endl;
return 0;
}