Merge branch 'develop' of github.com:paboyle/Grid into develop

Grid/Grid.h

@@ -42,6 +42,7 @@ Author: paboyle <paboyle@ph.ed.ac.uk>
 #include <Grid/GridQCDcore.h>
 #include <Grid/qcd/action/Action.h>
 #include <Grid/qcd/utils/GaugeFix.h>
+#include <Grid/qcd/utils/CovariantSmearing.h>
 #include <Grid/qcd/smearing/Smearing.h>
 #include <Grid/parallelIO/MetaData.h>
 #include <Grid/qcd/hmc/HMC_aggregate.h>

Grid/qcd/utils/CovariantSmearing.h

@@ -0,0 +1,87 @@
+/*************************************************************************************
+
+Grid physics library, www.github.com/paboyle/Grid
+
+Source file: ./lib/qcd/action/scalar/CovariantLaplacian.h
+
+Copyright (C) 2016
+
+Author: Azusa Yamaguchi
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+See the full license in the file "LICENSE" in the top level distribution
+directory
+*************************************************************************************/
+#pragma once
+
+namespace Grid {
+namespace QCD {
+
+template <class Gimpl> class CovariantSmearing : public Gimpl 
+{
+public:
+  INHERIT_GIMPL_TYPES(Gimpl);
+
+  typedef typename Gimpl::GaugeLinkField GaugeMat;
+  typedef typename Gimpl::GaugeField GaugeLorentz;
+
+  template<typename T>
+  static void GaussianSmear(const std::vector<LatticeColourMatrix>& U, 
+			    T& chi, 
+			    const Real& width, int Iterations, int orthog)
+  {
+    GridBase *grid = chi._grid;
+    T psi(grid);
+
+    ////////////////////////////////////////////////////////////////////////////////////
+    // Follow Chroma conventions for width to keep compatibility with previous data
+    // Free field iterates 
+    //   chi = (1 - w^2/4N p^2)^N chi
+    //
+    //       ~ (e^(-w^2/4N p^2)^N chi
+    //       ~ (e^(-w^2/4 p^2) chi
+    //       ~ (e^(-w'^2/2 p^2) chi          [ w' = w/sqrt(2) ]
+    //
+    // Which in coordinate space is proportional to
+    //
+    //   e^(-x^2/w^2) = e^(-x^2/2w'^2) 
+    //
+    // The 4 is a bit unconventional from Gaussian width perspective, but... it's Chroma convention.
+    // 2nd derivative approx d^2/dx^2  =  x+mu + x-mu - 2x
+    //
+    // d^2/dx^2 = - p^2
+    //
+    // chi = ( 1 + w^2/4N d^2/dx^2 )^N chi
+    //
+    ////////////////////////////////////////////////////////////////////////////////////
+    Real coeff = (width*width) / Real(4*Iterations);
+  
+    int dims = Nd;
+    if( orthog < Nd ) dims=Nd-1;
+
+    for(int n = 0; n < Iterations; ++n) {
+      psi = (-2.0*dims)*chi;
+      for(int mu=0;mu<Nd;mu++) {
+	if ( mu != orthog ) { 
+	  psi = psi + Gimpl::CovShiftForward(U[mu],mu,chi);    
+	  psi = psi + Gimpl::CovShiftBackward(U[mu],mu,chi);    
+	}
+      }
+      chi = chi + coeff*psi;
+    }
+  }
+};
+}}

tests/smearing/Test_smearing.cc

@@ -0,0 +1,73 @@
+/*
+ *
+
+    Grid physics library, www.github.com/paboyle/Grid
+
+    Source file: ./tests/Test_wilson_cg_prec.cc
+
+    Copyright (C) 2015
+
+Author: Peter Boyle <paboyle@ph.ed.ac.uk>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+    See the full license in the file "LICENSE" in the top level distribution directory
+    *************************************************************************************/
+    /*  END LEGAL */
+#include <Grid/Grid.h>
+
+using namespace std;
+using namespace Grid;
+using namespace Grid::QCD;
+
+
+int main (int argc, char ** argv)
+{
+  Grid_init(&argc,&argv);
+
+
+  std::vector<int> latt_size   = GridDefaultLatt();
+  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplex::Nsimd());
+  std::vector<int> mpi_layout  = GridDefaultMpi();
+  GridCartesian               Grid(latt_size,simd_layout,mpi_layout);
+
+  std::vector<int> seeds({1,2,3,4});
+  GridParallelRNG          pRNG(&Grid);  pRNG.SeedFixedIntegers(seeds);
+
+  LatticeFermion src(&Grid); random(pRNG,src);
+  RealD nrm = norm2(src);
+  LatticeFermion result(&Grid); result=zero;
+  LatticeGaugeField Umu(&Grid);
+  //  SU3::HotConfiguration(pRNG,Umu);
+  SU3::ColdConfiguration(Umu);
+  std::vector<LatticeColourMatrix> U(4,&Grid);
+
+  for(int mu=0;mu<Nd;mu++){
+    U[mu] = PeekIndex<LorentzIndex>(Umu,mu);
+  }
+
+  std::vector<int> site({4,4,0,0});
+  src=zero;
+  SpinColourVector scv;
+  scv=zero;
+  scv()(0)(0) = 1.0;
+  pokeSite(scv,src,site);
+
+  CovariantSmearing<PeriodicGimplR>::GaussianSmear(U, src, 2.0, 50, Tdir);
+
+  std::cout << src <<std::endl;
+  
+}
+