5 files changed, 474 insertions, 0 deletions
diff --git a/examples/src/models/roughening/CMakeLists.txt b/examples/src/models/roughening/CMakeLists.txt
new file mode 100644
index 0000000..51a8644
--- /dev/null
+++ b/examples/src/models/roughening/CMakeLists.txt
@@ -0,0 +1,21 @@
+
+add_executable(wolff_dgm             wolff_dgm.cpp)
+add_executable(wolff_cgm             wolff_cgm.cpp)
+
+find_library(GL NAMES GL)
+find_library(GLU NAMES GLU)
+find_library(GLUT NAMES glut)
+
+if (${GLUT} MATCHES "GLUT-NOTFOUND")
+  target_link_libraries(wolff_dgm             wolff wolff_examples)
+  target_link_libraries(wolff_cgm             wolff wolff_examples)
+else()
+  target_compile_definitions(wolff_dgm             PUBLIC HAVE_GLUT)
+  target_compile_definitions(wolff_cgm             PUBLIC HAVE_GLUT)
+
+  target_link_libraries(wolff_dgm             wolff wolff_examples glut GL GLU)
+  target_link_libraries(wolff_cgm             wolff wolff_examples glut GL GLU)
+endif()
+
+install(TARGETS wolff_dgm wolff_cgm DESTINATION ${CMAKE_INSTALL_BINDIR})
+
diff --git a/examples/src/models/roughening/dihedral_inf.hpp b/examples/src/models/roughening/dihedral_inf.hpp
new file mode 100644
index 0000000..19fa195
--- /dev/null
+++ b/examples/src/models/roughening/dihedral_inf.hpp
@@ -0,0 +1,47 @@
+
+#include <wolff/types.h>
+#include <cmath>
+#include "height.hpp"
+
+template <class T>
+class dihedral_inf_t {
+  public:
+  bool is_reflection;
+  T x;
+
+  dihedral_inf_t() : is_reflection(false), x(0) {}
+  dihedral_inf_t(bool x, T y) : is_reflection(x), x(y) {}
+
+  height_t<T> act(const height_t<T>& h) const {
+    if (this->is_reflection) {
+      return height_t(this->x - h.x);
+    } else {
+      return height_t(this->x + h.x);
+    }
+  }
+
+  dihedral_inf_t<T> act(const dihedral_inf_t<T>& r) const {
+    if (this->is_reflection) {
+      return dihedral_inf_t<T>(!r.is_reflection, this->x - r.x);
+    } else {
+      return dihedral_inf_t<T>(r.is_reflection, this->x + r.x);
+    }
+  }
+
+  height_t<T> act_inverse(const height_t<T>& h) const {
+    if (this->is_reflection) {
+      return this->act(h);
+    } else {
+      return height_t(h.x - this->x);
+    }
+  }
+
+  dihedral_inf_t<T> act_inverse(const dihedral_inf_t<T>& r) const {
+    if (this->is_reflection) {
+      return this->act(r);
+    } else {
+      return dihedral_inf_t<T>(r.is_reflection, r.x - this->x);
+    }
+  }
+};
+
diff --git a/examples/src/models/roughening/height.hpp b/examples/src/models/roughening/height.hpp
new file mode 100644
index 0000000..4023063
--- /dev/null
+++ b/examples/src/models/roughening/height.hpp
@@ -0,0 +1,75 @@
+
+#pragma once
+
+#include <cmath>
+#include <stdio.h>
+
+#include <wolff/types.h>
+
+/* The following is the minimum definition of a spin class.
+ *
+ * The class must contain an M_t and an F_t for holding the sum of an
+ * integer number of spins and a double-weighted number of spins,
+ * respectively.
+ *
+ * void init(X_t *p);
+ * void free_spin(X_t p);
+ * void free_spin(M_t p);
+ * void free_spin(F_t p);
+ * X_t copy(X_t x);
+ * void add(M_t *x1, int factor, X_t x2);
+ * void add(F_t *x1, double factor, X_t x2);
+ * M_t scalar_multiple(int factor, X_t x);
+ * F_t scalar_multiple(double factor, X_t x);
+ * double norm_squared(F_t x);
+ * void write_magnetization(M_t M, FILE *outfile);
+ *
+ */
+
+template <class T>
+struct height_t {
+  T x;
+
+  typedef T M_t;
+  typedef double F_t;
+
+  height_t() : x(0) {}
+
+  height_t(T x) : x(x) {}
+
+  inline T operator*(v_t a) const {
+    return x * a;
+  }
+
+  inline double operator*(double a) const {
+    return x * a;
+  }
+
+  inline T operator-(const height_t& h) const {
+    return x - h.x;
+  }
+};
+
+template <class T>
+inline T& operator+=(T& M, const height_t<T> &h) {
+  M += h.x;
+
+  return M;
+}
+
+template <class T>
+inline T& operator-=(T& M, const height_t<T> &h) {
+  M -= h.x;
+
+  return M;
+}
+
+double norm_squared(double h) {
+  return pow(h, 2);
+}
+
+template <class T>
+void write_magnetization(T M, FILE *outfile) {
+  fwrite(&M, sizeof(T), 1, outfile);
+}
+
diff --git a/examples/src/models/roughening/wolff_cgm.cpp b/examples/src/models/roughening/wolff_cgm.cpp
new file mode 100644
index 0000000..65f8d66
--- /dev/null
+++ b/examples/src/models/roughening/wolff_cgm.cpp
@@ -0,0 +1,167 @@
+
+#include <getopt.h>
+
+#ifdef HAVE_GLUT
+#include <GL/glut.h>
+#endif
+
+// include your group and spin space
+#include "dihedral_inf.hpp"
+#include "height.hpp"
+
+#include <randutils/randutils.hpp>
+
+// include wolff.h
+#include <wolff.hpp>
+
+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
+  randutils::auto_seed_128 seeds;
+  std::mt19937 rng{seeds};
+
+  // define spin-spin coupling
+  std::function <double(const height_t<double>&, const height_t<double>&)> Z = [] (const height_t<double>& h1, const 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>(std::mt19937&, height_t<double>)> gen_R = [=] (std::mt19937& r, height_t<double> h) -> dihedral_inf_t<double> {
+    dihedral_inf_t<double> rot;
+    rot.is_reflection = true;
+    std::normal_distribution<double> dist(0.0,1.0);
+
+    double amount = epsilon * dist(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
+
+#ifdef HAVE_GLUT
+    // 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 = (s.R.act_inverse(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 = (s.R.act_inverse(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();
+    };
+#endif
+  }
+
+  // run wolff for N cluster flips
+  wolff(N, s, gen_R, measurement, rng, 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
+
+  if (draw) {
+  }
+
+  return 0;
+
+}
+
diff --git a/examples/src/models/roughening/wolff_dgm.cpp b/examples/src/models/roughening/wolff_dgm.cpp
new file mode 100644
index 0000000..8395382
--- /dev/null
+++ b/examples/src/models/roughening/wolff_dgm.cpp
@@ -0,0 +1,164 @@
+
+#include <getopt.h>
+
+#ifdef HAVE_GLUT
+#include <GL/glut.h>
+#endif
+
+// include your group and spin space
+#include "dihedral_inf.hpp"
+#include "height.hpp"
+
+#include <randutils/randutils.hpp>
+
+// include wolff.h
+#include <wolff.hpp>
+
+typedef state_t <dihedral_inf_t<int64_t>, height_t<int64_t>> 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;
+  uint64_t 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
+  randutils::auto_seed_128 seeds;
+  std::mt19937 rng{seeds};
+
+  // define spin-spin coupling
+  std::function <double(const height_t<int64_t>&, const height_t<int64_t>&)> Z = [] (const height_t<int64_t>& h1, const height_t<int64_t>& h2) -> double {
+    return -pow(h1.x - h2.x, 2);
+  };
+
+  // define spin-field coupling
+  std::function <double(const height_t<int64_t> &)> B = [=] (const height_t<int64_t>& 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<int64_t>(std::mt19937&, height_t<int64_t>)> gen_R = [=] (std::mt19937& r, height_t<int64_t> h) -> dihedral_inf_t<int64_t> {
+    dihedral_inf_t<int64_t> rot;
+    rot.is_reflection = true;
+
+    std::uniform_int_distribution<int64_t> dist(-epsilon,epsilon);
+
+    rot.x = 2 * h.x + dist(r);
+
+    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
+
+#ifdef HAVE_GLUT
+    // 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);
+      int64_t max_h = INT64_MIN;
+      int64_t min_h = INT64_MAX;
+      for (v_t i = 0; i < pow(L, 2); i++) {
+        int64_t cur_h = (s.R.act_inverse(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++) {
+        int64_t cur_h = (s.R.act_inverse(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();
+    };
+#endif
+  }
+
+  // run wolff for N cluster flips
+  wolff(N, s, gen_R, measurement, rng, 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);
+
+  if (draw) {
+  }
+
+  return 0;
+
+}
+