Got the NERSC IO working and fixed a bug in cshift.

tests/Grid_cshift.cc

@@ -0,0 +1,84 @@
+#include <Grid.h>
+#include <parallelIO/GridNerscIO.h>
+
+using namespace std;
+using namespace Grid;
+using namespace Grid::QCD;
+
+int main (int argc, char ** argv)
+{
+  Grid_init(&argc,&argv);
+
+  std::vector<int> simd_layout({1,1,2,2});
+  std::vector<int> mpi_layout ({2,2,2,2});
+  std::vector<int> latt_size  ({8,8,8,16});
+    
+  GridCartesian     Fine(latt_size,simd_layout,mpi_layout);
+  GridRNG           FineRNG(&Fine);
+
+  LatticeComplex U(&Fine);
+  LatticeComplex ShiftU(&Fine);
+
+  LatticeComplex lex(&Fine);
+  lex=zero;
+  Integer stride =1;
+  {
+    double nrm;
+    LatticeComplex coor(&Fine);
+
+    for(int d=0;d<4;d++){
+      LatticeCoordinate(coor,d);
+      lex = lex + coor*stride;
+      stride=stride*latt_size[d];
+    }
+    U=lex;
+  }
+
+  TComplex cm;
+  
+  for(int dir=0;dir<4;dir++){
+    for(int shift=0;shift<latt_size[dir];shift++){
+      if ( Fine.IsBoss() ) 
+	std::cout<<"Shifting by "<<shift<<" in direction"<<dir<<std::endl;
+
+	ShiftU  = Cshift(U,dir,shift);    // Shift everything
+
+	std::vector<int> coor(4);
+
+	for(coor[3]=0;coor[3]<latt_size[3];coor[3]++){
+	for(coor[2]=0;coor[2]<latt_size[2];coor[2]++){
+	for(coor[1]=0;coor[1]<latt_size[1];coor[1]++){
+	for(coor[0]=0;coor[0]<latt_size[0];coor[0]++){
+	  
+	  peekSite(cm,ShiftU,coor);
+
+	  double nrm=norm2(U);
+
+	  std::vector<int> scoor(coor);
+	  scoor[dir] = (scoor[dir]+shift)%latt_size[dir];
+	  
+	  Integer slex = scoor[0]
+	    + latt_size[0]*scoor[1]
+	    + latt_size[0]*latt_size[1]*scoor[2]
+	    + latt_size[0]*latt_size[1]*latt_size[2]*scoor[3];
+
+	  Complex scm(slex);
+	  
+	  nrm = abs(scm-cm()()());
+	  std::vector<int> peer(4);
+	  int index=real(cm);
+	  Fine.CoorFromIndex(peer,index,latt_size);
+
+	  if (nrm > 0){
+	    cout<<"FAIL shift "<< shift<<" in dir "<< dir<<" ["<<coor[0]<<","<<coor[1]<<","<<coor[2]<<","<<coor[3]<<"] = "<< cm()()()<<" expect "<<scm<<"  "<<nrm<<endl;
+	    cout<<"Got    "<<index<<" " << peer[0]<<","<<peer[1]<<","<<peer[2]<<","<<peer[3]<<std::endl;
+	    index=real(scm);
+	    Fine.CoorFromIndex(peer,index,latt_size);
+	    cout<<"Expect "<<index<<" " << peer[0]<<","<<peer[1]<<","<<peer[2]<<","<<peer[3]<<std::endl;
+	  }
+	}}}}
+    }
+  }
+
+  Grid_finalize();
+}

tests/Grid_nersc_io.cc

@@ -0,0 +1,62 @@
+#include <Grid.h>
+#include <parallelIO/GridNerscIO.h>
+
+using namespace std;
+using namespace Grid;
+using namespace Grid::QCD;
+
+
+int main (int argc, char ** argv)
+{
+  Grid_init(&argc,&argv);
+
+  std::vector<int> simd_layout({1,1,2,2});
+  std::vector<int> mpi_layout ({2,1,1,2});
+  std::vector<int> latt_size  ({16,16,16,32});
+    
+  GridCartesian     Fine(latt_size,simd_layout,mpi_layout);
+  GridRNG           FineRNG(&Fine);
+  LatticeGaugeField Umu(&Fine);
+
+  std::vector<LatticeColourMatrix> U(4,&Fine);
+  
+  NerscField header;
+  
+  std::string file("./ckpoint_lat.4000");
+  readNerscConfiguration(Umu,header,file);
+
+  for(int mu=0;mu<Nd;mu++){
+    U[mu] = peekIndex<3>(Umu,mu);
+  }
+
+  // Painful ; fix syntactical niceness
+  LatticeComplex LinkTrace(&Fine);
+  LinkTrace=zero;
+  for(int mu=0;mu<Nd;mu++){
+    LinkTrace = LinkTrace + trace(U[mu]);
+  }
+
+  // (1+2+3)=6 = N(N-1)/2 terms
+  LatticeComplex Plaq(&Fine);
+  Plaq = zero;
+  for(int mu=1;mu<Nd;mu++){
+    for(int nu=0;nu<mu;nu++){
+      Plaq = Plaq + trace(U[mu]*Cshift(U[nu],mu,1)*adj(Cshift(U[mu],nu,1))*adj(U[nu]));
+    }
+  }
+
+
+  double vol = Fine.gSites();
+
+  Complex PlaqScale(1.0/vol/6.0/3.0);
+  TComplex Tp = sum(Plaq);
+  Complex p  = TensorRemove(Tp);
+  std::cout << "calculated plaquettes " <<p*PlaqScale<<std::endl;
+
+  Complex LinkTraceScale(1.0/vol/4.0/3.0);
+  TComplex Tl = sum(LinkTrace);
+  Complex l  = TensorRemove(Tl);
+  std::cout << "calculated link trace " <<l*LinkTraceScale<<std::endl;
+
+  Grid_finalize();
+}

tests/Makefile.am

@@ -5,10 +5,16 @@ AM_LDFLAGS = -L$(top_srcdir)/lib
 #
 # Test code
 #
-bin_PROGRAMS = Grid_main test_Grid_stencil
+bin_PROGRAMS = Grid_main test_Grid_stencil Grid_nersc_io Grid_cshift
 
 Grid_main_SOURCES = Grid_main.cc
 Grid_main_LDADD = -lGrid
 
+Grid_nersc_io_SOURCES = Grid_nersc_io.cc
+Grid_nersc_io_LDADD = -lGrid
+
+Grid_cshift_SOURCES = Grid_cshift.cc
+Grid_cshift_LDADD = -lGrid
+
 test_Grid_stencil_SOURCES = test_Grid_stencil.cc
 test_Grid_stencil_LDADD = -lGrid