Added 1mr+ algorithm.

[phys/heatbath.git] / sim-1mr+.hpp

diff --git a/sim-1mr+.hpp b/sim-1mr+.hpp
new file mode 100644 (file)
index 0000000..8902558
--- /dev/null
+++ b/sim-1mr+.hpp
@@ -0,0 +1,82 @@
+#ifndef SIM_HPP
+#define SIM_HPP
+
+#include <gsl/gsl_rng.h>
+#include <complex>
+#include <math.h>
+
+#include "latlib/neigh.h"
+
+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;
+  void updatePhi (const int& x);
+};
+
+
+
+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::updatePhi (const int& x) 
+{
+  complex<double> V=0;
+  const double theta = gsl_rng_uniform(rangsl) * 2*M_PI;
+
+  for (int nu=0; nu<4; nu++)
+    V += conf[ (*nb)[x*4+nu] ].phi;
+
+  const double V2diff = pow(real(V), 2) - pow(imag(V), 2);
+  const double Vprod = real(V)*imag(V);
+  conf[x].phi = complex<double> ( + real(conf[x].phi) * V2diff + 2 * imag(conf[x].phi) * Vprod,
+                                 - imag(conf[x].phi) * V2diff + 2 * real(conf[x].phi) * Vprod ) / norm(V);
+  
+  const double r = exp( - M * norm(conf[x].phi)
+                       - 1./M * norm(V)
+                       + 2 * real( conf[x].phi * conj(V) ) );
+  
+  conf[x].phi = sqrt(std::log( 1./(1-r) )) / sqrt(M)
+    * complex<double>( cos(theta), sin(theta) )
+    + V / M;
+}
+
+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;
+}
+
+#endif