Added optional user defined number of guard cells to use with PSATD solver (#787)

* Added optional user defined number of quard cells to use with PSATD solver.

* Removed temporary comments.

* Changed names nx_guard_psatd to psatd.nx_guard for consistency.

1 files changed, 13 insertions, 14 deletions

diff --git a/Source/Parallelization/GuardCellManager.cpp b/Source/Parallelization/GuardCellManager.cpp
index 8e4eca183..f36c64214 100644
--- a/Source/Parallelization/GuardCellManager.cpp
+++ b/Source/Parallelization/GuardCellManager.cpp
@@ -6,9 +6,8 @@
  */
 #include "GuardCellManager.H"
 #include "Filter/NCIGodfreyFilter.H"
-
 #include <AMReX_Print.H>
-
+#include <AMReX_ParmParse.H>
 
 using namespace amrex;
 
@@ -29,12 +28,6 @@ guardCellManager::Init(
     const amrex::Array<amrex::Real,3> v_galilean,
     const bool safe_guard_cells)
 {
-#ifndef WARPX_USE_PSATD
-    (void)do_fft_mpi_dec;
-    (void)nox_fft;
-    (void)noy_fft;
-    (void)noz_fft;
-#endif
     // When using subcycling, the particles on the fine level perform two pushes
     // before being redistributed ; therefore, we need one extra guard cell
     // (the particles may move by 2*c*dt)
@@ -110,12 +103,18 @@ guardCellManager::Init(
         // the stencil of the FFT solver. Here, this number (`ngFFT`)
         // is determined *empirically* to be the order of the solver
         // for nodal, and half the order of the solver for staggered.
-        IntVect ngFFT;
-        if (do_nodal) {
-            ngFFT = IntVect(AMREX_D_DECL(nox_fft, noy_fft, noz_fft));
-        } else {
-            ngFFT = IntVect(AMREX_D_DECL(nox_fft/2, noy_fft/2, noz_fft/2));
-        }
+
+        int ngFFt_x = do_nodal ? nox_fft : nox_fft/2.;
+        int ngFFt_y = do_nodal ? noy_fft : noy_fft/2.;
+        int ngFFt_z = do_nodal ? noz_fft : noz_fft/2.;
+
+        ParmParse pp("psatd");
+        pp.query("nx_guard", ngFFt_x);
+        pp.query("ny_guard", ngFFt_y);
+        pp.query("nz_guard", ngFFt_z);
+
+        IntVect ngFFT = IntVect(AMREX_D_DECL(ngFFt_x, ngFFt_y, ngFFt_z));
+
         for (int i_dim=0; i_dim<AMREX_SPACEDIM; i_dim++ ){
             int ng_required = ngFFT[i_dim];
             // Get the max