From e44e2da31a4240600590eb9a564db0e0e586cba1 Mon Sep 17 00:00:00 2001
From: Jaron Kent-Dobias <jaron@kent-dobias.com>
Date: Mon, 23 Jul 2018 14:04:13 -0400
Subject: anddddd also did the (trivial) continuous gaussian model by flipping
 all the int64_ts in dgm to doubles

---
 src/wolff_cgm.cpp | 163 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 163 insertions(+)
 create mode 100644 src/wolff_cgm.cpp

(limited to 'src')

diff --git a/src/wolff_cgm.cpp b/src/wolff_cgm.cpp
new file mode 100644
index 0000000..559f6fc
--- /dev/null
+++ b/src/wolff_cgm.cpp
@@ -0,0 +1,163 @@
+
+#include <getopt.h>
+
+#ifdef HAVE_GLUT
+#include <GL/glut.h>
+#endif
+
+// include your group and spin space
+#include <dihedral_inf.h>
+#include <height.h>
+
+// include wolff.h
+#include <wolff.h>
+
+typedef state_t <dihedral_inf_t<double>, height_t<double>> sim_t;
+
+int main(int argc, char *argv[]) {
+
+  count_t N = (count_t)1e4;
+
+  D_t D = 2;
+  L_t L = 128;
+  double T = 2.26918531421;
+  double H = 0;
+
+  bool silent = false;
+  bool draw = false;
+  unsigned int window_size = 512;
+  double epsilon = 1;
+
+  int opt;
+
+  while ((opt = getopt(argc, argv, "N:D:L:T:H:sdw:e:")) != -1) {
+    switch (opt) {
+    case 'N': // number of steps
+      N = (count_t)atof(optarg);
+      break;
+    case 'D': // dimension
+      D = atoi(optarg);
+      break;
+    case 'L': // linear size
+      L = atoi(optarg);
+      break;
+    case 'T': // temperature 
+      T = atof(optarg);
+      break;
+    case 'H': // external field. nth call couples to state n
+      H = atof(optarg);
+      break;
+    case 'e': // external field. nth call couples to state n
+      epsilon = atof(optarg);
+      break;
+    case 's': // don't print anything during simulation. speeds up slightly
+      silent = true;
+      break;
+    case 'd':
+#ifdef HAVE_GLUT
+      draw = true;
+      break;
+#else
+      printf("You didn't compile this with the glut library installed!\n");
+      exit(EXIT_FAILURE);
+#endif
+    case 'w':
+      window_size = atoi(optarg);
+      break;
+    default:
+      exit(EXIT_FAILURE);
+    }
+  }
+
+  // initialize random number generator
+  gsl_rng *r = gsl_rng_alloc(gsl_rng_mt19937);
+  gsl_rng_set(r, rand_seed());
+
+  // define spin-spin coupling
+  std::function <double(height_t<double>, height_t<double>)> Z = [] (height_t<double> h1, height_t<double> h2) -> double {
+    return -pow(h1.x - h2.x, 2);
+  };
+
+  // define spin-field coupling
+  std::function <double(height_t<double>)> B = [=] (height_t<double> h) -> double {
+    return -H * pow(h.x, 2);;
+  };
+
+  // initialize state object
+  sim_t s(D, L, T, Z, B);
+
+  // define function that generates self-inverse rotations
+  std::function <dihedral_inf_t<double>(gsl_rng *, height_t<double>)> gen_R = [=] (gsl_rng *r, height_t<double> h) -> dihedral_inf_t<double> {
+    dihedral_inf_t<double> rot;
+    rot.is_reflection = true;
+
+    double amount = epsilon * gsl_ran_ugaussian(r);
+
+    rot.x = 2 * h.x + amount;
+
+    return rot;
+  };
+
+  // define function that updates any number of measurements
+  std::function <void(const sim_t *)> measurement;
+
+  double average_M = 0;
+  if (!draw) {
+    // a very simple example: measure the average magnetization
+    measurement = [&] (const sim_t *s) {
+      average_M += (double)s->M / (double)N / (double)s->nv;
+    };
+  } else {
+    // a more complex example: measure the average magnetization, and draw the spin configuration to the screen
+
+    // initialize glut
+    glutInit(&argc, argv);
+    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
+    glutInitWindowSize(window_size, window_size);
+    glutCreateWindow("wolff");
+    glClearColor(0.0,0.0,0.0,0.0);
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    gluOrtho2D(0.0, L, 0.0, L);
+
+    measurement = [&] (const sim_t *s) {
+      average_M += (double)s->M / (double)N / (double)s->nv;
+      glClear(GL_COLOR_BUFFER_BIT);
+      double max_h = INT64_MIN;
+      double min_h = INT64_MAX;
+      for (v_t i = 0; i < pow(L, 2); i++) {
+        double cur_h = act_inverse(s->R, s->spins[i]).x;
+        if (cur_h < min_h) {
+          min_h = cur_h;
+        }
+        if (cur_h > max_h) {
+          max_h = cur_h;
+        }
+      }
+
+      for (v_t i = 0; i < pow(L, 2); i++) {
+        double cur_h = act_inverse(s->R, s->spins[i]).x;
+        double mag = ((double)(cur_h - min_h)) / ((double)(max_h - min_h));
+        glColor3f(mag, mag, mag);
+        glRecti(i / L, i % L, (i / L) + 1, (i % L) + 1);
+      }
+      glFlush();
+    };
+  }
+
+  // run wolff for N cluster flips
+  wolff(N, &s, gen_R, measurement, r, silent);
+
+  // tell us what we found!
+  printf("%" PRIcount " DGM runs completed. D = %" PRID ", L = %" PRIL ", T = %g, H = %g, <M> = %g\n", N, D, L, T, H, average_M);
+
+  // free the random number generator
+  gsl_rng_free(r);
+
+  if (draw) {
+  }
+
+  return 0;
+
+}
+
-- 
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