mirror of
https://github.com/triqs/dft_tools
synced 2024-11-01 03:33:50 +01:00
62 lines
2.3 KiB
C++
62 lines
2.3 KiB
C++
/*******************************************************************************
|
|
*
|
|
* TRIQS: a Toolbox for Research in Interacting Quantum Systems
|
|
*
|
|
* Copyright (C) 2012 by O. Parcollet
|
|
*
|
|
* TRIQS 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 3 of the License, or (at your option) any later
|
|
* version.
|
|
*
|
|
* TRIQS 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
|
|
* TRIQS. If not, see <http://www.gnu.org/licenses/>.
|
|
*
|
|
******************************************************************************/
|
|
#ifndef TRIQS_ARRAYS_BLAS_LAPACK_DSTEV_H
|
|
#define TRIQS_ARRAYS_BLAS_LAPACK_DSTEV_H
|
|
#include "./tools.hpp"
|
|
|
|
namespace triqs { namespace arrays { namespace blas {
|
|
|
|
using namespace blas_lapack_tools;
|
|
namespace f77 { // overload
|
|
|
|
extern "C" {
|
|
void TRIQS_FORTRAN_MANGLING(dstev)(const char *, const int &N, const double [], const double [], const double [], const int &, double [], int &);
|
|
}
|
|
|
|
inline void stev (char J, const int & N, double* D, double* E, double* Z, int ldz, double * work, int & info) {
|
|
TRIQS_FORTRAN_MANGLING(dstev)(&J,N,D,E,Z,ldz,work,info);
|
|
}
|
|
}
|
|
|
|
struct tridiag_worker {
|
|
arrays::vector<double> D,E,W;
|
|
matrix<double> Z;
|
|
size_t s;
|
|
tridiag_worker (size_t n){ s=0; resize(n);}
|
|
void resize(size_t n) { if (s<n) {D.resize(n); E.resize(n); W.resize(n); Z.resize(n,n);} s = n; }
|
|
template<typename VT>
|
|
void operator()(VT const & d, VT const & e) {
|
|
if (e.size() != d.size() -1) TRIQS_RUNTIME_ERROR << " Error in tridiagonal matrix diagonalization size mismatch";
|
|
resize(d.size());
|
|
D(range(0,s)) = d;
|
|
E(range(0,s-1)) = e;
|
|
int info;
|
|
f77::stev ('V',d.size(),D.data_start(),E.data_start(), Z.data_start(), Z.shape(0),W.data_start(), info);
|
|
if (info !=0) TRIQS_RUNTIME_ERROR << " Error in tridiagonal matrix diagonalization "<< info;
|
|
}
|
|
arrays::vector_view<double> values() const { return D(range(0,s));}
|
|
matrix_view<double> vectors() const { return Z(range(0,s),range(0,s));}
|
|
};
|
|
|
|
}}}// namespace
|
|
#endif
|
|
|