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Starting to modified KS

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This commit is contained in:
Chulwoo Jung
2025-11-26 22:13:27 +00:00
parent fe0ab5f1a9
commit d5ac4fc67f
2 changed files with 37 additions and 23 deletions
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34
Grid/algorithms/iterative/KrylovSchur.h
View File

@@ -89,6 +89,14 @@ struct ComplexComparator
RitzFilter RF;
ComplexComparator (RitzFilter _rf) : RF(_rf) {}
bool operator()(std::complex<double> z1, std::complex<double> z2) {
RealD tmp1, tmp2;
tmp1=std::abs(std::imag(z1));
tmp2=std::abs(std::imag(z2));
// if ( std::abs(std::real(z1)) <0.76) tmp1 +=4.;
// if ( std::abs(std::real(z2)) <0.76) tmp2 +=4.;
if ( std::abs(std::real(z1)) >2.) tmp1 +=4.;
if ( std::abs(std::real(z2)) >2.) tmp2 +=4.;
switch (RF) {
case EvalNormSmall:
return std::abs(z1) < std::abs(z2);
@@ -103,9 +111,11 @@ struct ComplexComparator
case EvalImLarge:
return std::imag(z1) > std::imag(z2);
case EvalImNormSmall:
return std::abs(std::imag(z1)) < std::abs(std::imag(z2));
return tmp1 < tmp2;
// return std::abs(std::imag(z1)) < std::abs(std::imag(z2));
case EvalImNormLarge:
return std::abs(std::imag(z1)) > std::abs(std::imag(z2));
return tmp1 > tmp2;
// return std::abs(std::imag(z1)) > std::abs(std::imag(z2));
default:
assert(0);
}
@@ -224,8 +234,8 @@ class ComplexSchurDecomposition {
*/
// void schurReorder(int Nk, std::function compare) {
int schurReorder(int Nk) {
for (int i = 0; i < Nm; i++) {
for (int k = 0; k <= Nm - 2; k++) {
for (int i = 0; i < Nk; i++) {
for (int k = 0; k <= Nm - 2-i ; k++) {
int idx = Nm - 2 - k;
// TODO use RitzFilter enum here
// if (std::abs(S(idx, idx)) < std::abs(S(idx+1, idx+1))) { // sort by largest modulus of eigenvalue
@@ -235,10 +245,10 @@ class ComplexSchurDecomposition {
}
}
}
int temp=1;
for (int i = 0; i < Nm-1; i++) {
int temp=Nk/2;
for (int i = temp; i < Nk; i++) {
std::cout << GridLogMessage << "S " << i << " "<<std::real(S(i,i))<<" "<<std::imag(S(i,i)) << std::endl;
if (std::abs(std::imag(S(i,i))< 0.01)) temp= i+1;
if (std::abs(std::imag(S(i,i)))< 0.01) temp= i+1;
}
return temp;
}
@@ -341,13 +351,13 @@ class KrylovSchur {
int start = 0;
Field startVec = v0;
littleEvecs = Eigen::MatrixXcd::Zero(Nm, Nm);
int Nconv=Nstop;
for (int i = 0; i < MaxIter; i++) {
std::cout << GridLogMessage << "Restart Iteration " << i << std::endl;
// Perform Arnoldi steps to compute Krylov basis and Rayleigh quotient (Hess)
arnoldiIteration(startVec, Nm, start, doubleOrthog);
startVec = u; // original code
start = Nk;
// checkKSDecomposition();
@@ -359,7 +369,10 @@ class KrylovSchur {
// Rearrange Schur matrix so wanted evals are on top left (like MATLAB's ordschur)
std::cout << GridLogMessage << "Reordering Schur eigenvalues Nk=" << Nk << std::endl;
// Nk=schur.schurReorder(_Nk);
schur.schurReorder(Nk);
// start = Nk;
schur.schurReorder(_Nk);
Nk = (Nconv+_Nk)/2;
start=Nk;
std::cout << GridLogMessage << "After Reorder Nk= "<<Nk<<std::endl;
Eigen::MatrixXcd Q = schur.getMatrixQ();
Qt = Q.adjoint(); // TODO should Q be real?
@@ -414,7 +427,7 @@ class KrylovSchur {
std::cout << GridLogMessage << "Eigenvalues (first Nk sorted): " << std::endl << evals << std::endl;
// check convergence and return if needed.
int Nconv = converged();
Nconv = converged();
std::cout << GridLogMessage << "Number of evecs converged: " << Nconv << std::endl;
if (Nconv >= Nstop || i == MaxIter - 1) {
std::cout << GridLogMessage << "Converged with " << Nconv << " / " << Nstop << " eigenvectors on iteration "
@@ -469,7 +482,6 @@ class KrylovSchur {
u = Zero();
} else {
std::cout << GridLogMessage << "start= " <<start<< " basis.size= "<<basis.size()<<std::endl;
// assert( start <= basis.size() ); // should be starting at the end of basis (start = Nk)
// assert( start == basis.size() ); // should be starting at the end of basis (start = Nk)
std::cout << GridLogMessage << "Resetting Rayleigh and b" << std::endl;
Eigen::MatrixXcd RayleighCp = Rayleigh;

26
examples/Example_krylov_schur.cc
View File

@@ -51,6 +51,7 @@ struct LanczosParameters: Serializable {
Integer, Nk,
Integer, Np,
Integer, ReadEvec,
Integer, maxIter,
RealD, resid,
RealD, ChebyLow,
RealD, ChebyHigh,
@@ -453,18 +454,6 @@ int main (int argc, char ** argv)
write(HMCwr,"LanczosParameters",LanParams);
}
#if 0
if(LanParams.ReadEvec) {
std::string evecs_file="evec_in";
std::cout << GridLogIRL<< "Reading evecs from "<<evecs_file<<std::endl;
emptyUserRecord record;
Grid::ScidacReader RD;
RD.open(evecs_file);
RD.readScidacFieldRecord(src,record);
RD.close();
}
#endif
RealD mass=0.01;
RealD M5=1.8;
@@ -521,11 +510,24 @@ int main (int argc, char ** argv)
Nstop=LanParams.Nstop;
Nk=LanParams.Nk;
Np=LanParams.Np;
maxIter=LanParams.maxIter;
Nm = Nk + Np;
int Nu=16;
std::vector<LatticeFermion> src(Nu,FGrid);
for(int i=0;i<Nu;i++) random(RNG5,src[i]);
#if 1
if(LanParams.ReadEvec) {
std::string evecs_file="evec_in";
std::cout << GridLogIRL<< "Reading evecs from "<<evecs_file<<std::endl;
emptyUserRecord record;
Grid::ScidacReader RD;
RD.open(evecs_file);
RD.readScidacFieldRecord(src[0],record);
RD.close();
}
#endif
Coordinate origin ({0,0,0,0});
auto tmpSrc = peekSite(src[0], origin);
std::cout << "[DEBUG] Source at origin = " << tmpSrc << std::endl;