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Make PrecGCR recursive - it can precondition itself

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This commit is contained in:
Peter Boyle 2020-01-27 12:42:48 -05:00
parent 086256a032
commit b2736ec80b
1 changed files with 26 additions and 44 deletions
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70
Grid/algorithms/iterative/PrecGeneralisedConjugateResidual.h
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@ -38,10 +38,11 @@ Author: Peter Boyle <paboyle@ph.ed.ac.uk>
///////////////////////////////////////////////////////////////////////////////////////////////////////
NAMESPACE_BEGIN(Grid);
#define GCRLogLevel std::cout << GridLogMessage <<std::string(level,'\t')<< " Level "<<level<<" "
template<class Field>
class PrecGeneralisedConjugateResidual : public OperatorFunction<Field> {
class PrecGeneralisedConjugateResidual : public LinearFunction<Field> {
public:
using OperatorFunction<Field>::operator();
RealD Tolerance;
Integer MaxIterations;
@ -49,23 +50,29 @@ public:
int mmax;
int nstep;
int steps;
int level;
GridStopWatch PrecTimer;
GridStopWatch MatTimer;
GridStopWatch LinalgTimer;
LinearFunction<Field> &Preconditioner;
LinearFunction<Field> &Preconditioner;
LinearOperatorBase<Field> &Linop;
PrecGeneralisedConjugateResidual(RealD tol,Integer maxit,LinearFunction<Field> &Prec,int _mmax,int _nstep) :
void Level(int lv) { level=lv; };
PrecGeneralisedConjugateResidual(RealD tol,Integer maxit,LinearOperatorBase<Field> &_Linop,LinearFunction<Field> &Prec,int _mmax,int _nstep) :
Tolerance(tol),
MaxIterations(maxit),
Linop(_Linop),
Preconditioner(Prec),
mmax(_mmax),
nstep(_nstep)
{
level=1;
verbose=1;
};
void operator() (LinearOperatorBase<Field> &Linop,const Field &src, Field &psi){
void operator() (const Field &src, Field &psi){
psi=Zero();
RealD cp, ssq,rsq;
@ -84,9 +91,9 @@ public:
steps=0;
for(int k=0;k<MaxIterations;k++){
cp=GCRnStep(Linop,src,psi,rsq);
cp=GCRnStep(src,psi,rsq);
std::cout<<GridLogMessage<<"VPGCR("<<mmax<<","<<nstep<<") "<< steps <<" steps cp = "<<cp<<" target "<<rsq <<std::endl;
GCRLogLevel <<"PGCR("<<mmax<<","<<nstep<<") "<< steps <<" steps cp = "<<cp<<" target "<<rsq <<std::endl;
if(cp<rsq) {
@ -95,24 +102,26 @@ public:
Linop.HermOp(psi,r);
axpy(r,-1.0,src,r);
RealD tr = norm2(r);
std::cout<<GridLogMessage<<"PrecGeneralisedConjugateResidual: Converged on iteration " <<steps
GCRLogLevel<<"PGCR: Converged on iteration " <<steps
<< " computed residual "<<sqrt(cp/ssq)
<< " true residual " <<sqrt(tr/ssq)
<< " target " <<Tolerance <<std::endl;
std::cout<<GridLogMessage<<"VPGCR Time elapsed: Total "<< SolverTimer.Elapsed() <<std::endl;
std::cout<<GridLogMessage<<"VPGCR Time elapsed: Precon "<< PrecTimer.Elapsed() <<std::endl;
std::cout<<GridLogMessage<<"VPGCR Time elapsed: Matrix "<< MatTimer.Elapsed() <<std::endl;
std::cout<<GridLogMessage<<"VPGCR Time elapsed: Linalg "<< LinalgTimer.Elapsed() <<std::endl;
GCRLogLevel<<"PGCR Time elapsed: Total "<< SolverTimer.Elapsed() <<std::endl;
/*
GCRLogLevel<<"PGCR Time elapsed: Precon "<< PrecTimer.Elapsed() <<std::endl;
GCRLogLevel<<"PGCR Time elapsed: Matrix "<< MatTimer.Elapsed() <<std::endl;
GCRLogLevel<<"PGCR Time elapsed: Linalg "<< LinalgTimer.Elapsed() <<std::endl;
*/
return;
}
}
std::cout<<GridLogMessage<<"Variable Preconditioned GCR did not converge"<<std::endl;
GCRLogLevel<<"Variable Preconditioned GCR did not converge"<<std::endl;
assert(0);
}
RealD GCRnStep(LinearOperatorBase<Field> &Linop,const Field &src, Field &psi,RealD rsq){
RealD GCRnStep(const Field &src, Field &psi,RealD rsq){
RealD cp;
RealD a, b;
@ -134,9 +143,7 @@ public:
std::vector<Field> p(mmax,grid);
std::vector<RealD> qq(mmax);
std::cout<<GridLogIterative<< " ************** "<< std::endl;
std::cout<<GridLogIterative<< " GCRnStep("<<nstep<<")"<<std::endl;
std::cout<<GridLogIterative<< " ************** "<< std::endl;
GCRLogLevel<< "PGCR nStep("<<nstep<<")"<<std::endl;
//////////////////////////////////
// initial guess x0 is taken as nonzero.
@ -150,35 +157,15 @@ public:
LinalgTimer.Start();
r=src-Az;
LinalgTimer.Stop();
std::cout<<GridLogIterative<< " GCRnStep true residual r = src - A psi "<<norm2(r) <<std::endl;
GCRLogLevel<< "PGCR true residual r = src - A psi "<<norm2(r) <<std::endl;
/////////////////////
// p = Prec(r)
/////////////////////
std::cout<<GridLogIterative<< " GCRnStep apply preconditioner z= M^-1 r "<< std::endl;
std::cout<<GridLogIterative<< " --------------------------------------- "<< std::endl;
PrecTimer.Start();
Preconditioner(r,z);
PrecTimer.Stop();
std::cout<<GridLogIterative<< " --------------------------------------- "<< std::endl;
std::cout<<GridLogIterative<< " GCRnStep called Preconditioner z "<< norm2(z) <<std::endl;
// MatTimer.Start();
// Linop.HermOp(z,tmp);
// MatTimer.Stop();
// LinalgTimer.Start();
// ttmp=tmp;
// tmp=tmp-r;
// LinalgTimer.Stop();
/*
std::cout<<GridLogMessage<<r<<std::endl;
std::cout<<GridLogMessage<<z<<std::endl;
std::cout<<GridLogMessage<<ttmp<<std::endl;
std::cout<<GridLogMessage<<tmp<<std::endl;
*/
MatTimer.Start();
Linop.HermOpAndNorm(z,Az,zAz,zAAz);
@ -190,7 +177,6 @@ public:
p[0]= z;
q[0]= Az;
qq[0]= zAAz;
std::cout<<GridLogIterative<< " GCRnStep p0=z, q0 = A p0 " <<std::endl;
cp =norm2(r);
LinalgTimer.Stop();
@ -212,20 +198,16 @@ public:
cp = axpy_norm(r,-a,q[peri_k],r);
LinalgTimer.Stop();
std::cout<<GridLogMessage<< " VPGCR_step["<<steps<<"] resid " << cp << " target " <<rsq<<std::endl;
GCRLogLevel<< "PGCR step["<<steps<<"] resid " << cp << " target " <<rsq<<std::endl;
if((k==nstep-1)||(cp<rsq)){
return cp;
}
std::cout<<GridLogIterative<< " GCRnStep apply preconditioner z= M^-1 r "<< std::endl;
std::cout<<GridLogIterative<< " --------------------------------------- "<< std::endl;
PrecTimer.Start();
Preconditioner(r,z);// solve Az = r
PrecTimer.Stop();
std::cout<<GridLogIterative<< " --------------------------------------- "<< std::endl;
std::cout<<GridLogIterative<< " GCRnStep called Preconditioner z "<< norm2(z) <<std::endl;
MatTimer.Start();
Linop.HermOpAndNorm(z,Az,zAz,zAAz);