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Grid/tests/Test_multishift_sqrt.cc
Peter Boyle dc66161f47 Change the SIMD command correctly with precision = double vs. single and
connect the "Real" default precisoin to a configure flag.
Have RealF, RealD and Real types, where Real is compile target dependent single/double,
RealF is single and RealD is double etc..
2015-07-01 22:45:15 +01:00

119 lines
2.9 KiB
C++

#include <Grid.h>
using namespace std;
using namespace Grid;
using namespace Grid::QCD;
template<class Field> class DumbOperator : public LinearOperatorBase<Field> {
public:
LatticeComplex scale;
LatticeComplex sqrtscale;
DumbOperator(GridBase *grid)
: scale(grid),
sqrtscale(grid)
{
GridParallelRNG pRNG(grid);
std::vector<int> seeds({5,6,7,8});
pRNG.SeedFixedIntegers(seeds);
random(pRNG,sqrtscale);
sqrtscale = sqrtscale * adj(sqrtscale);// force real pos def
scale = sqrtscale * sqrtscale;
}
// Support for coarsening to a multigrid
void OpDiag (const Field &in, Field &out) {};
void OpDir (const Field &in, Field &out,int dir,int disp){};
void Op (const Field &in, Field &out){
out = scale * in;
}
void AdjOp (const Field &in, Field &out){
out = scale * in;
}
void HermOp(const Field &in, Field &out){
double n1, n2;
HermOpAndNorm(in,out,n1,n2);
}
void HermOpAndNorm(const Field &in, Field &out,double &n1,double &n2){
ComplexD dot;
out = scale * in;
dot= innerProduct(in,out);
n1=real(dot);
dot = innerProduct(out,out);
n2=real(dot);
}
void ApplySqrt(const Field &in, Field &out){
out = sqrtscale * in;
}
};
int main (int argc, char ** argv)
{
Grid_init(&argc,&argv);
GridCartesian *grid = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(),
GridDefaultSimd(Nd,vComplex::Nsimd()),
GridDefaultMpi());
double lo=0.001;
double hi=1.0;
int precision=64;
int degree=10;
AlgRemez remez(lo,hi,precision);
////////////////////////////////////////
// sqrt and inverse sqrt
////////////////////////////////////////
std::cout << "Generating degree "<<degree<<" for x^(1/2)"<<std::endl;
remez.generateApprox(degree,1,2);
MultiShiftFunction Sqrt(remez,1.0e-6,false);
GridParallelRNG pRNG(grid);
std::vector<int> seeds({1,2,3,4});
pRNG.SeedFixedIntegers(seeds);
LatticeFermion src(grid); random(pRNG,src);
LatticeFermion combined(grid);
LatticeFermion reference(grid);
LatticeFermion error(grid);
std::vector<LatticeFermion> result(degree,grid);
LatticeFermion summed(grid);
ConjugateGradientMultiShift<LatticeFermion> MSCG(10000,Sqrt);
DumbOperator<LatticeFermion> Diagonal(grid);
MSCG(Diagonal,src,result);
// double a = norm;
// for(int n=0;n<poles.size();n++){
// a = a + residues[n]/(x+poles[n]);
// }
assert(Sqrt.order==degree);
combined = Sqrt.norm*src;
for(int i=0;i<degree;i++){
combined = combined + Sqrt.residues[i]*result[i];
}
Diagonal.ApplySqrt(src,reference);
error = reference - combined;
std::cout << " Reference "<<norm2(reference)<<std::endl;
std::cout << " combined "<<norm2(combined) <<std::endl;
std::cout << " error "<<norm2(error) <<std::endl;
MSCG(Diagonal,src,summed);
error = summed - combined;
std::cout << " summed-combined "<<norm2(error) <<std::endl;
Grid_finalize();
}