wip

Src/FFT/AMReX_FFT.H

@@ -48,7 +48,8 @@ private:
  Box m_spectral_domain;
 
  // assuming it's double for now
- fftw_plan m_fftw_plan_x = nullptr;
+ fftw_plan m_fftw_fwd_x = nullptr;
+ fftw_plan m_fftw_bwd_x = nullptr;
  fftw_plan m_fftw_plan_y = nullptr;
  fftw_plan m_fftw_plan_z = nullptr;
 

Src/FFT/AMReX_FFT.cpp

@@ -35,26 +35,35 @@ R2C::R2C (BoxArray const& ba, DistributionMapping const& dm, Box const& domain)
  double* in = m_rx[myproc].dataPtr();
  auto* out = (fftw_complex*)(m_cx[myproc].dataPtr());
 
- m_fftw_plan_x = fftw_plan_many_dft_r2c(1, &nxi, howmany,
- in, nullptr, 1, nxi,
- out, nullptr, 1, nxo,
- FFTW_ESTIMATE);
+ m_fftw_fwd_x = fftw_plan_many_dft_r2c(1, &nxi, howmany,
+ in, nullptr, 1, nxi,
+ out, nullptr, 1, nxo,
+ FFTW_ESTIMATE || FFTW_DESTROY_INPUT);
+ m_fftw_bwd_x = fftw_plan_many_dft_c2r(1, &nxi, howmany,
+ out, nullptr, 1, nxo,
+ in, nullptr, 1, nxi,
+ FFTW_ESTIMATE || FFTW_DESTROY_INPUT);
 }
 
 R2C::~R2C ()
 {
- fftw_destroy_plan(m_fftw_plan_x);
+ fftw_destroy_plan(m_fftw_fwd_x);
 }
 
 void R2C::forward_doit (MultiFab const& inmf, Scaling scaling)
 {
  m_rx.ParallelCopy(inmf, 0, 0, 1);
- fftw_execute(m_fftw_plan_x);
+ fftw_execute(m_fftw_fwd_x);
+
+ // xxxxx todo: scaling
 }
 
 void R2C::backward_doit (MultiFab& outmf, Scaling scaling)
 {
+ // xxxxx todo: scaling
 
+ fftw_execute(m_fftw_bwd_x);
+ outmf.ParallelCopy(m_rx, 0, 0, 1);
 }
 
 }

Tests/FFT/Poisson/main.cpp

@@ -1,6 +1,7 @@
 #include <AMReX.H>
 #include <AMReX_MultiFab.H>
 #include <AMReX_ParmParse.H>
+#include <AMReX_PlotFileUtil.H>
 
 #include <AMReX_FFT.H>
 
@@ -76,6 +77,8 @@ int main (int argc, char* argv[])
 
  FFT::R2C fft(ba, dm, geom.Domain());
  fft.forwardThenBackward(rhs, soln, post_forward);
+
+ VisMF::Write(soln, "soln");
  }
  amrex::Finalize();
 }