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Merge branch 'master' of https://github.com/paboyle/Grid

Browse Source 
Conflicts:
	lib/Make.inc
	tests/Make.inc
	tests/Test_remez.cc
This commit is contained in:
Peter Boyle
2015-06-08 12:08:09 +01:00
parent d6f1ddf99c 8688ff8b3a
commit 3111f50f2f
11 changed files with 453 additions and 54 deletions
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53
tests/Test_remez.cc
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@ -4,43 +4,6 @@ using namespace std;
using namespace Grid;
using namespace Grid::QCD;
class MultiShiftFunction {
public:
std::vector<double> poles;
std::vector<double> residues;
double norm;
double lo,hi;
MultiShiftFunction(int n,double _lo,double _hi): poles(n), residues(n), lo(_lo), hi(_hi) {;};
double approx(double x);
void csv(std::ostream &out);
void gnuplot(std::ostream &out);
};
double MultiShiftFunction::approx(double x)
{
double a = norm;
for(int n=0;n<poles.size();n++){
a = a + residues[n]/(x+poles[n]);
}
return a;
}
void MultiShiftFunction::gnuplot(std::ostream &out)
{
out<<"f(x) = "<<norm<<"";
for(int n=0;n<poles.size();n++){
out<<"+("<<residues[n]<<"/(x+"<<poles[n]<<"))";
}
out<<";"<<std::endl;
}
void MultiShiftFunction::csv(std::ostream &out)
{
for (double x=lo; x<hi; x*=1.05) {
double f = approx(x);
double r = std::sqrt(x);
out<< x<<","<<r<<","<<f<<","<<r-f<<std::endl;
}
return;
}
int main (int argc, char ** argv)
{
Grid_init(&argc,&argv);
@ -56,22 +19,18 @@ int main (int argc, char ** argv)
////////////////////////////////////////
// sqrt and inverse sqrt
////////////////////////////////////////
MultiShiftFunction Sqrt(degree,lo,hi);
MultiShiftFunction InvSqrt(degree,lo,hi);
MultiShiftFunction SqrtSqrt(degree,lo,hi);
MultiShiftFunction InvSqrtSqrt(degree,lo,hi);
std::cout << "Generating degree "<<degree<<" for x^(1/2)"<<std::endl;
remez.generateApprox(degree,1,2);
remez.getPFE (& Sqrt.residues[0],& Sqrt.poles[0],& Sqrt.norm);
remez.getIPFE(&InvSqrt.residues[0],&InvSqrt.poles[0],&InvSqrt.norm);
MultiShiftFunction Sqrt(remez,1.0,false);
MultiShiftFunction InvSqrt(remez,1.0,true);
std::cout << "Generating degree "<<degree<<" for x^(1/4)"<<std::endl;
remez.generateApprox(degree,1,4);
remez.getPFE (&SqrtSqrt.residues[0],&SqrtSqrt.poles[0],&SqrtSqrt.norm);
remez.getIPFE(&InvSqrtSqrt.residues[0],&InvSqrtSqrt.poles[0],&InvSqrtSqrt.norm);
MultiShiftFunction SqrtSqrt(remez,1.0,false);
MultiShiftFunction InvSqrtSqrt(remez,1.0,true);
ofstream gnuplot(std::string("Sqrt.gnu"),std::ios::out|std::ios::trunc);
Sqrt.gnuplot(gnuplot);