X-Git-Url: http://git.treefish.org/~alex/phys/heatbath.git/blobdiff_plain/0b059f97536bd764b5093652c93b0d060565a90d..b29c28bcd466d938ffd95887abef67dc1491bd50:/sim-metro.hpp

diff --git a/sim-metro.hpp b/sim-metro.hpp
new file mode 100644
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--- /dev/null
+++ b/sim-metro.hpp
@@ -0,0 +1,90 @@
+#ifndef SIM_HPP
+#define SIM_HPP
+
+#include <gsl/gsl_rng.h>
+#include <complex>
+#include <math.h>
+
+#include "latlib/neigh.h"
+
+#define EPSILONPHI 0.5
+
+class sim : public o815::sim {
+public:
+  struct siteconf {
+    complex<double> phi;
+  };
+  sim(o815 *_O815);
+  siteconf* conf;
+  unsigned int LSIZE2;
+  double M;
+  double m;
+  neigh *nb;
+
+private:
+  void _makeSweep();
+  void _newParas();
+  gsl_rng* rangsl;
+  int updatePhi (const int& x);
+  double SofPhi(const int& x, const complex<double>& phix);
+  double rhoPhi(const int& x, const complex<double>& phixCandidate);
+};
+
+
+
+sim::sim(o815 *_O815) : o815::sim( _O815, 
+				   sizeof(siteconf)*
+				   (_O815->comargs.lsize[0]*_O815->comargs.lsize[1]) ) {
+  conf = (siteconf*)confMem;
+
+  rangsl = gsl_rng_alloc(gsl_rng_ranlxs0);
+  gsl_rng_set(rangsl, time(NULL));
+
+  LSIZE2 = _O815->comargs.lsize[0] * _O815->comargs.lsize[1];
+
+  nb = new neigh(2, _O815->comargs.lsize[0], _O815->comargs.lsize[1]);
+}
+
+void sim::_makeSweep() {  
+  for (int ichecker=0; ichecker<2; ichecker++)
+    for (int it=0; it<O815->comargs.lsize[0]; it++)
+      for (int iy=(it+ichecker)%2; iy<O815->comargs.lsize[1]; iy+=2)
+	updatePhi( it*O815->comargs.lsize[1] + iy );
+}
+
+void sim::_newParas() {
+  m = (*O815->paraQ)["mass"];
+  M = pow( (*O815->paraQ)["mass"], 2 ) + 4;
+  *log << "SIM: Resetting fields." << endl << flush;
+
+  for (int ix=0; ix<LSIZE2; ix++)
+    conf[ix].phi = 1;
+}
+
+int sim::updatePhi(const int& x) {
+  complex<double> phixCandidate = conf[x].phi +
+    complex<double> ( 2*EPSILONPHI*( 0.5 - gsl_rng_uniform(rangsl) ), 
+		      2*EPSILONPHI*( 0.5 - gsl_rng_uniform(rangsl) ) );
+  
+  if ( gsl_rng_uniform(rangsl) < rhoPhi(x, phixCandidate) ) {
+    conf[x].phi = phixCandidate;
+    return 1;
+  }
+  
+  return 0;
+}
+
+double sim::rhoPhi(const int& x, const complex<double>& phixCandidate) {
+  return exp( SofPhi(x, conf[x].phi) - SofPhi(x, phixCandidate) );
+}
+
+double sim::SofPhi(const int& x, const complex<double>& phix) {
+  double sofphi = M * norm(phix);
+  
+  for (int nu=0; nu<4; nu++)
+    sofphi -= 2 * real( conj(phix) * conf[ (*nb)[x*4+nu] ].phi );
+  
+  return sofphi;
+}
+
+#endif