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EvenOdd schur decomposed mpcdagmpc version of rhmc determinant.

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dH is also small and plaquette looks right.
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Peter Boyle
2015-08-18 18:37:39 +01:00
parent 9c7840c3a7
commit 48db72259e
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185
lib/qcd/action/pseudofermion/OneFlavourEvenOddRational.h Normal file
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#ifndef QCD_PSEUDOFERMION_ONE_FLAVOUR_EVEN_ODD_RATIONAL_H
#define QCD_PSEUDOFERMION_ONE_FLAVOUR_EVEN_ODD_RATIONAL_H
namespace Grid{
namespace QCD{
///////////////////////////////////////
// One flavour rational
///////////////////////////////////////
// S_f = chi^dag * N(Mpc^dag*Mpc)/D(Mpc^dag*Mpc) * chi
//
// Here, M is some operator
// N and D makeup the rat. poly
//
template<class Impl>
class OneFlavourEvenOddRationalPseudoFermionAction : public Action<typename Impl::GaugeField> {
public:
INHERIT_IMPL_TYPES(Impl);
typedef OneFlavourRationalParams Params;
Params param;
MultiShiftFunction PowerHalf ;
MultiShiftFunction PowerNegHalf;
MultiShiftFunction PowerQuarter;
MultiShiftFunction PowerNegQuarter;
private:
FermionOperator<Impl> & FermOp;// the basic operator
// NOT using "Nroots"; IroIro is -- perhaps later, but this wasn't good for us historically
// and hasenbusch works better
FermionField PhiEven; // the pseudo fermion field for this trajectory
FermionField PhiOdd; // the pseudo fermion field for this trajectory
public:
OneFlavourEvenOddRationalPseudoFermionAction(FermionOperator<Impl> &Op,
Params & p ) : FermOp(Op),
PhiEven(Op.FermionRedBlackGrid()),
PhiOdd (Op.FermionRedBlackGrid()),
param(p)
{
AlgRemez remez(param.lo,param.hi,param.precision);
// MdagM^(+- 1/2)
std::cout<<GridLogMessage << "Generating degree "<<param.degree<<" for x^(1/2)"<<std::endl;
remez.generateApprox(param.degree,1,2);
PowerHalf.Init(remez,param.tolerance,false);
PowerNegHalf.Init(remez,param.tolerance,true);
// MdagM^(+- 1/4)
std::cout<<GridLogMessage << "Generating degree "<<param.degree<<" for x^(1/4)"<<std::endl;
remez.generateApprox(param.degree,1,4);
PowerQuarter.Init(remez,param.tolerance,false);
PowerNegQuarter.Init(remez,param.tolerance,true);
};
virtual void init(const GaugeField &U, GridParallelRNG& pRNG) {
// P(phi) = e^{- phi^dag (MpcdagMpc)^-1/2 phi}
// = e^{- phi^dag (MpcdagMpc)^-1/4 (MpcdagMpc)^-1/4 phi}
// Phi = MpcdagMpc^{1/4} eta
//
// P(eta) = e^{- eta^dag eta}
//
// e^{x^2/2 sig^2} => sig^2 = 0.5.
//
// So eta should be of width sig = 1/sqrt(2).
RealD scale = std::sqrt(0.5);
FermionField eta (FermOp.FermionGrid());
FermionField etaOdd (FermOp.FermionRedBlackGrid());
FermionField etaEven(FermOp.FermionRedBlackGrid());
gaussian(pRNG,eta); eta=eta*scale;
pickCheckerboard(Even,etaEven,eta);
pickCheckerboard(Odd,etaOdd,eta);
FermOp.ImportGauge(U);
// mutishift CG
SchurDifferentiableOperator<Impl> Mpc(FermOp);
ConjugateGradientMultiShift<FermionField> msCG(param.MaxIter,PowerQuarter);
msCG(Mpc,etaOdd,PhiOdd);
//////////////////////////////////////////////////////
// FIXME : Clover term not yet..
//////////////////////////////////////////////////////
assert(FermOp.ConstEE() == 1);
PhiEven = zero;
};
//////////////////////////////////////////////////////
// S = phi^dag (Mdag M)^-1/2 phi
//////////////////////////////////////////////////////
virtual RealD S(const GaugeField &U) {
FermOp.ImportGauge(U);
FermionField Y(FermOp.FermionRedBlackGrid());
SchurDifferentiableOperator<Impl> Mpc(FermOp);
ConjugateGradientMultiShift<FermionField> msCG(param.MaxIter,PowerNegQuarter);
msCG(Mpc,PhiOdd,Y);
RealD action = norm2(Y);
std::cout << GridLogMessage << "Pseudofermion action FIXME -- is -1/4 solve or -1/2 solve faster??? "<<action<<std::endl;
return action;
};
//////////////////////////////////////////////////////
// Need
// dS_f/dU = chi^dag d[N/D] chi
//
// N/D is expressed as partial fraction expansion:
//
// a0 + \sum_k ak/(M^dagM + bk)
//
// d[N/D] is then
//
// \sum_k -ak [M^dagM+bk]^{-1} [ dM^dag M + M^dag dM ] [M^dag M + bk]^{-1}
//
// Need
// Mf Phi_k = [MdagM+bk]^{-1} Phi
// Mf Phi = \sum_k ak [MdagM+bk]^{-1} Phi
//
// With these building blocks
//
// dS/dU = \sum_k -ak Mf Phi_k^dag [ dM^dag M + M^dag dM ] Mf Phi_k
// S = innerprodReal(Phi,Mf Phi);
//////////////////////////////////////////////////////
virtual void deriv(const GaugeField &U,GaugeField & dSdU) {
const int Npole = PowerNegHalf.poles.size();
std::vector<FermionField> MPhi_k (Npole,FermOp.FermionRedBlackGrid());
FermionField X(FermOp.FermionRedBlackGrid());
FermionField Y(FermOp.FermionRedBlackGrid());
GaugeField tmp(FermOp.GaugeGrid());
FermOp.ImportGauge(U);
SchurDifferentiableOperator<Impl> Mpc(FermOp);
ConjugateGradientMultiShift<FermionField> msCG(param.MaxIter,PowerNegHalf);
msCG(Mpc,PhiOdd,MPhi_k);
dSdU = zero;
for(int k=0;k<Npole;k++){
RealD ak = PowerNegHalf.residues[k];
X = MPhi_k[k];
Mpc.Mpc(X,Y);
Mpc.MpcDeriv (tmp , Y, X ); dSdU=dSdU+ak*tmp;
Mpc.MpcDagDeriv(tmp , X, Y ); dSdU=dSdU+ak*tmp;
}
dSdU = Ta(dSdU);
};
};
}
}
#endif