SelectionMatrix.h

#ifndef PBAT_MATH_LINALG_SELECTION_MATRIX_H
#define PBAT_MATH_LINALG_SELECTION_MATRIX_H
 
#include "pbat/Aliases.h"
 
namespace pbat {
namespace math {
namespace linalg {

template <class TDerivedC>
CSCMatrix SelectionMatrix(Eigen::DenseBase<TDerivedC> const& C, Index n = Index(-1))
{
    if (n < 0)
        n = C.maxCoeff() + 1;
    CSCMatrix S(n, C.size());
    S.reserve(IndexVectorX::Ones(C.size()));
    for (auto c = 0; c < C.size(); ++c)
        S.insert(C(c), c) = Scalar(1);
    return S;
}
 
} // namespace linalg
} // namespace math
} // namespace pbat
 
#endif // PBAT_MATH_LINALG_SELECTION_MATRIX_H