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Grid/lib/algorithms/iterative/EigenSort.h
2016-03-30 00:16:02 -07:00

82 lines
2.6 KiB
C++

/*************************************************************************************
Grid physics library, www.github.com/paboyle/Grid
Source file: ./lib/algorithms/iterative/EigenSort.h
Copyright (C) 2015
Author: Peter Boyle <paboyle@ph.ed.ac.uk>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
See the full license in the file "LICENSE" in the top level distribution directory
*************************************************************************************/
/* END LEGAL */
#ifndef GRID_EIGENSORT_H
#define GRID_EIGENSORT_H
namespace Grid {
/////////////////////////////////////////////////////////////
// Eigen sorter to begin with
/////////////////////////////////////////////////////////////
template<class Field>
class SortEigen {
private:
//hacking for testing for now
private:
static bool less_lmd(RealD left,RealD right){
return left > right;
}
static bool less_pair(std::pair<RealD,Field const*>& left,
std::pair<RealD,Field const*>& right){
return left.first > (right.first);
}
public:
void push(DenseVector<RealD>& lmd,
DenseVector<Field>& evec,int N) {
DenseVector<Field> cpy(lmd.size(),evec[0]._grid);
for(int i=0;i<lmd.size();i++) cpy[i] = evec[i];
DenseVector<std::pair<RealD, Field const*> > emod(lmd.size());
for(int i=0;i<lmd.size();++i)
emod[i] = std::pair<RealD,Field const*>(lmd[i],&cpy[i]);
partial_sort(emod.begin(),emod.begin()+N,emod.end(),less_pair);
typename DenseVector<std::pair<RealD, Field const*> >::iterator it = emod.begin();
for(int i=0;i<N;++i){
lmd[i]=it->first;
evec[i]=*(it->second);
++it;
}
}
void push(DenseVector<RealD>& lmd,int N) {
std::partial_sort(lmd.begin(),lmd.begin()+N,lmd.end(),less_lmd);
}
bool saturated(RealD lmd, RealD thrs) {
return fabs(lmd) > fabs(thrs);
}
};
}
#endif