matrix_pointset.h

// Description: Matrix columns as a point-set
// Documentation: pointset.txt

#ifndef PASTELMATH_MATRIX_POINTSET_H
#define PASTELMATH_MATRIX_POINTSET_H

#include <pastel/sys/pointset/pointset_concept.h>
#include <pastel/sys/set/sparse_set.h>
#include <pastel/sys/set/interval_set.h>
#include <pastel/sys/locator/pointerrange_locator.h>

#include <armadillo>

namespace Pastel
{

    //! Constructs a point-set from the columns of a matrix.
    /*
   Preconditions:
   The matrix is stored in column-major order.

   Optional arguments:

   dBegin, dEnd (0 <= integer <= set.n_rows):
   The range of rows which use as the coordinates 
   of the points. 
   Default: 0, set.n_rows.
   */
    template <
        typename Real,
        typename... ArgumentSet>
    decltype(auto) matrixPointSet(
        const arma::Mat<Real>& set,
        ArgumentSet&&... argumentSet)
    {
        const integer dBegin = PASTEL_ARG_S(dBegin, 0);
        const integer dEnd = PASTEL_ARG_S(dEnd, set.n_rows);

        ENSURE_OP(dBegin, >=, 0);
        ENSURE_OP(dBegin, <, dEnd);
        ENSURE_OP(dEnd, <=, set.n_rows);

        return locationSet(
            sparseSet(
                intervalSet(set.memptr(), set.memptr() + set.size()), 
                set.n_rows), 
            PointerRange_Locator<real>(dBegin, dEnd));
    }

}

#endif