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Adding threshold in Plaquette testing fft5d bugfix

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This commit is contained in:
Chulwoo Jung
2026-05-08 18:53:30 -04:00
parent d5cab295b2
commit bb99123e6d
3 changed files with 276 additions and 14 deletions
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examples/fft5d.cc
+16 -12
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@@ -237,36 +237,39 @@ static void trajFFT(const std::vector<LatticeComplexD>& in,
GridBase* g = in[0].Grid();
long lsites = g->lSites();
// Pack: buf[traj * lsites + lsite] (traj varies slowly, site varies fast)
std::vector<fftw_complex> ibuf((long)Ntraj * lsites);
// fftw_complex is double[2] — std::vector<double[2]> is not supported by nvcc.
// Use std::vector<double> with 2x size and reinterpret_cast.
std::vector<double> ibuf((long)Ntraj * lsites * 2, 0.0);
for (int n = 0; n < Ntraj; n++) {
std::vector<ComplexD> lc;
unvectorizeToLexOrdArray(lc, in[n]);
for (long s = 0; s < lsites; s++) {
ibuf[(long)n*lsites + s][0] = lc[s].real();
ibuf[(long)n*lsites + s][1] = lc[s].imag();
ibuf[((long)n*lsites + s)*2 + 0] = lc[s].real();
ibuf[((long)n*lsites + s)*2 + 1] = lc[s].imag();
}
}
// lsites transforms of length Ntraj, stride=lsites, dist=1
std::vector<fftw_complex> obuf((long)Ntraj * lsites);
std::vector<double> obuf((long)Ntraj * lsites * 2, 0.0);
fftw_complex* iptr = reinterpret_cast<fftw_complex*>(ibuf.data());
fftw_complex* optr = reinterpret_cast<fftw_complex*>(obuf.data());
int n1[1] = {Ntraj};
fftw_plan p = fftw_plan_many_dft(
1, n1, (int)lsites,
ibuf.data(), nullptr, (int)lsites, 1,
obuf.data(), nullptr, (int)lsites, 1,
iptr, nullptr, (int)lsites, 1,
optr, nullptr, (int)lsites, 1,
FFTW_FORWARD, FFTW_ESTIMATE);
fftw_execute(p);
fftw_destroy_plan(p);
// vector::assign triggers _M_fill_assign which needs a default constructor;
// Lattice has none. Use explicit push_back instead.
// Lattice has none. Use explicit emplace_back instead.
out.clear(); out.reserve(Ntraj);
for (int k = 0; k < Ntraj; k++) out.emplace_back(g);
for (int k = 0; k < Ntraj; k++) {
std::vector<ComplexD> lc(lsites);
for (long s = 0; s < lsites; s++)
lc[s] = ComplexD(obuf[(long)k*lsites+s][0], obuf[(long)k*lsites+s][1]);
lc[s] = ComplexD(obuf[((long)k*lsites+s)*2], obuf[((long)k*lsites+s)*2+1]);
vectorizeFromLexOrdArray(lc, out[k]);
}
}
@@ -311,10 +314,11 @@ static void analyzeTraj(const std::vector<LatticeComplexD>& traj,
}
// Autocorrelation via IFFT of the power spectrum
std::vector<fftw_complex> Pc(Nf);
for (int k = 0; k < Nf; k++) { Pc[k][0] = Pavg[k]; Pc[k][1] = 0.0; }
std::vector<double> Pc_buf(Nf * 2, 0.0);
for (int k = 0; k < Nf; k++) { Pc_buf[k*2] = Pavg[k]; Pc_buf[k*2+1] = 0.0; }
fftw_complex* Pc = reinterpret_cast<fftw_complex*>(Pc_buf.data());
std::vector<double> acorr(Ntraj, 0.0);
fftw_plan ip = fftw_plan_dft_c2r(1, &Ntraj, Pc.data(), acorr.data(), FFTW_ESTIMATE);
fftw_plan ip = fftw_plan_dft_c2r(1, &Ntraj, Pc, acorr.data(), FFTW_ESTIMATE);
fftw_execute(ip); fftw_destroy_plan(ip);
double c0 = acorr[0] / Ntraj;
{