158 lines
4.0 KiB
C++
158 lines
4.0 KiB
C++
//DIIS convergence acceleration according to Pulay: Chem. Phys. Lett. 73, 393 (1980); J. Comp. Chem. 3,556 (1982)
|
|
#ifndef _DIIS_H_
|
|
#define _DIIS_H_
|
|
#include "vec.h"
|
|
#include "smat.h"
|
|
#include "mat.h"
|
|
#include "sparsemat.h"
|
|
#include "nonclass.h"
|
|
#include "la_traits.h"
|
|
#include "auxstorage.h"
|
|
|
|
//Pulay memorial book remarks - for numerical stabilization small addition to diagonal
|
|
#define DIISEPS 1e-9
|
|
|
|
// Typically, T is some solution vector in form of NRVec, NRMat, or NRSMat over double or complex<double> fields
|
|
// actually it can be anything what has operator=(const T&), clear(), dot() , axpy(), norm() and copyonwrite(), and LA_traits<T>::normtype and elementtype
|
|
// and get() and put() if external storage is requested
|
|
|
|
template<typename T, typename U>
|
|
class DIIS
|
|
{
|
|
int dim;
|
|
int aktdim;
|
|
bool incore;
|
|
int cyclicshift; //circular buffer of last dim vectors
|
|
typedef typename LA_traits<T>::elementtype Te;
|
|
typedef typename LA_traits<U>::elementtype Ue;
|
|
NRSMat<Ue> bmat;
|
|
AuxStorage<Te> *st;
|
|
AuxStorage<Ue> *errst;
|
|
T *stor;
|
|
U *errstor;
|
|
public:
|
|
DIIS() {dim=0; st=NULL; stor=NULL; errst=NULL; errstor=NULL;}; //for array of diis
|
|
DIIS(const int n, const bool core=1);
|
|
void setup(const int n, const bool core=1);
|
|
~DIIS();
|
|
typename LA_traits<U>::normtype extrapolate(T &vec, const U &errvec, bool verbose=false); //vec is input/output; returns square residual norm
|
|
};
|
|
|
|
template<typename T, typename U>
|
|
DIIS<T,U>::DIIS(const int n, const bool core) : dim(n), incore(core), bmat(n+1,n+1)
|
|
{
|
|
st=incore?NULL: new AuxStorage<Te>;
|
|
errst=incore?NULL: new AuxStorage<Ue>;
|
|
stor= incore? new T[dim] : NULL;
|
|
errstor= incore? new U[dim] : NULL;
|
|
bmat= (Ue)0; for(int i=1; i<=n; ++i) bmat(0,i) = (Ue)-1;
|
|
aktdim=cyclicshift=0;
|
|
}
|
|
|
|
template<typename T, typename U>
|
|
void DIIS<T,U>::setup(const int n, const bool core)
|
|
{
|
|
dim=n;
|
|
incore=core;
|
|
bmat.resize(n+1);
|
|
st=incore?NULL: new AuxStorage<Te>;
|
|
errst=incore?NULL: new AuxStorage<Ue>;
|
|
stor= incore? new T[dim] : NULL;
|
|
errstor= incore? new U[dim] : NULL;
|
|
bmat= (Ue)0; for(int i=1; i<=n; ++i) bmat(0,i) = (Ue)-1;
|
|
aktdim=cyclicshift=0;
|
|
}
|
|
|
|
|
|
template<typename T, typename U>
|
|
DIIS<T,U>::~DIIS()
|
|
{
|
|
if(st) delete st;
|
|
if(errst) delete errst;
|
|
if(stor) delete[] stor;
|
|
if(errstor) delete[] errstor;
|
|
}
|
|
|
|
|
|
|
|
template<typename T, typename U>
|
|
typename LA_traits<U>::normtype DIIS<T,U>::extrapolate(T &vec, const U &errvec, bool verbose)
|
|
{
|
|
if(!dim) laerror("attempt to extrapolate from uninitialized DIIS");
|
|
//if dim exceeded, shift
|
|
if(aktdim==dim)
|
|
{
|
|
cyclicshift=(cyclicshift+1)%dim;
|
|
for(int i=1; i<dim; ++i)
|
|
for(int j=1; j<=i; ++j)
|
|
bmat(i,j)=bmat(i+1,j+1);
|
|
}
|
|
else
|
|
++aktdim;
|
|
|
|
//store vector
|
|
if(incore)
|
|
{
|
|
stor[(aktdim-1+cyclicshift)%dim]|=vec;
|
|
errstor[(aktdim-1+cyclicshift)%dim]|=errvec;
|
|
}
|
|
else
|
|
{
|
|
st->put(vec,(aktdim-1+cyclicshift)%dim);
|
|
errst->put(errvec,(aktdim-1+cyclicshift)%dim);
|
|
}
|
|
|
|
if(aktdim==1) return (typename LA_traits<T>::normtype)1;
|
|
|
|
|
|
//calculate overlaps of the new error with old ones
|
|
typename LA_traits<T>::normtype norm=errvec.norm();
|
|
bmat(aktdim,aktdim)= norm*norm + DIISEPS;
|
|
if(incore)
|
|
for(int i=1; i<aktdim; ++i)
|
|
bmat(i,aktdim)=errvec.dot(errstor[(i+cyclicshift-1)%dim]);
|
|
else
|
|
{
|
|
U tmp = errvec; tmp.copyonwrite(); //copy dimensions
|
|
for(int i=1; i<aktdim; ++i)
|
|
{
|
|
errst->get(tmp,(i-1+cyclicshift)%dim);
|
|
bmat(i,aktdim)= errvec.dot(tmp);
|
|
}
|
|
}
|
|
|
|
|
|
//prepare rhs-solution vector
|
|
NRVec<Ue> rhs(dim+1);
|
|
rhs= (Ue)0; rhs[0]= (Ue)-1;
|
|
|
|
//solve for coefficients
|
|
//@@@@@@ implement checking for bad condition number and eliminating old vectors
|
|
//@@@ explicit solution - cf. remarks in Pulay memorial book
|
|
{
|
|
NRSMat<Te> amat=bmat;
|
|
linear_solve(amat,rhs,NULL,aktdim+1);
|
|
}
|
|
if(verbose) cout <<"DIIS coefficients: "<<rhs<<endl;
|
|
|
|
//build the new linear combination
|
|
vec.clear();
|
|
if(incore)
|
|
for(int i=1; i<=aktdim; ++i)
|
|
vec.axpy(rhs[i],stor[(i-1+cyclicshift)%dim]);
|
|
else
|
|
{
|
|
T tmp=vec; //copy dimensions
|
|
for(int i=1; i<=aktdim; ++i)
|
|
{
|
|
st->get(tmp,(i-1+cyclicshift)%dim);
|
|
vec.axpy(rhs[i],tmp);
|
|
}
|
|
}
|
|
|
|
return norm;
|
|
}
|
|
|
|
|
|
#endif
|