addTransposedMatrix.hh

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
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/*   This file is part of the C++-library RFFGen.                              */
/*   Copyright 2015 Lars Lubkoll                                               */
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#ifndef RFFGEN_UTIL_ADDTRANSPOSEDMATRIX_HH
#define RFFGEN_UTIL_ADDTRANSPOSEDMATRIX_HH

#include <cassert>
#include <type_traits>
#include "../LinearAlgebra/dimension.hh"
#include "../Util/staticChecks.hh"

namespace RFFGen
{
  template <class Matrix ,
            class = std::enable_if_t<Checks::isConstantSizeMatrix<Matrix>()> >
  Matrix addTransposed(Matrix& A)
  {
    using Index = decltype(LinearAlgebra::dimension<Matrix>());
    for(Index i=0; i<LinearAlgebra::dimension<Matrix>(); ++i)
      for(Index j=i+1; j<LinearAlgebra::dimension<Matrix>(); ++j)
        at(A,j,i) = at(A,i,j) = at(A,i,j) + at(A,j,i);
    for(Index i=0; i<LinearAlgebra::dimension<Matrix>(); ++i) at(A,i,i) *= 2;
    return A;
  }

  template <class Matrix ,
            class = std::enable_if_t<!Checks::isConstantSizeMatrix<Matrix>()> ,
            class = std::enable_if_t<Checks::isDynamicMatrix<Matrix>()> >
  Matrix addTransposed(Matrix& A)
  {
    assert( LinearAlgebra::rows(A) == LinearAlgebra::cols(A) );
    using Index = decltype(LinearAlgebra::rows(std::declval<Matrix>()));
    for(Index i=0; i<LinearAlgebra::rows(A); ++i)
      for(Index j=i+1; j<LinearAlgebra::cols(A); ++j)
        at(A,j,i) = at(A,i,j) = at(A,i,j) + at(A,j,i);
    for(Index i=0; i<LinearAlgebra::rows(A); ++i) at(A,i,i) *= 2;
    return A;
  }
}

#endif // RFFGEN_UTIL_ADDTRANSPOSEDMATRIX_HH