now using const passing of object reference instead of pointers

13 files changed, 107 insertions, 386 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 12fe087..fe564f7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -22,7 +22,6 @@ add_executable(wolff_4potts src/wolff_potts.cpp ${CPPSOURCES} ${CSOURCES})
 add_executable(wolff_7potts src/wolff_potts.cpp ${CPPSOURCES} ${CSOURCES})
 add_executable(wolff_3clock src/wolff_clock.cpp ${CPPSOURCES} ${CSOURCES})
 add_executable(wolff_5clock src/wolff_clock.cpp ${CPPSOURCES} ${CSOURCES})
-add_executable(wolff_planar2 src/wolff_O2.cpp ${CPPSOURCES} ${CSOURCES})
 add_executable(wolff_planar src/wolff_On.cpp ${CPPSOURCES} ${CSOURCES})
 add_executable(wolff_heisenberg src/wolff_On.cpp ${CPPSOURCES} ${CSOURCES})
 add_executable(analyze_correlations src/analyze_correlations.cpp ${CPPSOURCES} ${CSOURCES})
@@ -55,7 +54,6 @@ if (${GLUT} MATCHES "GLUT-NOTFOUND")
   target_link_libraries(wolff_5clock cblas gsl m)
   target_link_libraries(wolff_heisenberg cblas gsl m)
   target_link_libraries(wolff_planar cblas gsl m)
-  target_link_libraries(wolff_planar2 cblas gsl m)
 else()
   target_link_libraries(wolff_ising cblas gsl m glut GL GLU)
   target_link_libraries(wolff_dgm cblas gsl m glut GL GLU)
@@ -67,7 +65,6 @@ else()
   target_link_libraries(wolff_5clock cblas gsl m glut GL GLU)
   target_link_libraries(wolff_heisenberg cblas gsl m glut GL GLU)
   target_link_libraries(wolff_planar cblas gsl m glut GL GLU)
-  target_link_libraries(wolff_planar2 cblas gsl m glut GL GLU)
   target_compile_definitions(wolff_ising PUBLIC HAVE_GLUT)
   target_compile_definitions(wolff_dgm PUBLIC HAVE_GLUT)
   target_compile_definitions(wolff_cgm PUBLIC HAVE_GLUT)
@@ -77,7 +74,6 @@ else()
   target_compile_definitions(wolff_3clock PUBLIC HAVE_GLUT)
   target_compile_definitions(wolff_5clock PUBLIC HAVE_GLUT)
   target_compile_definitions(wolff_planar PUBLIC HAVE_GLUT)
-  target_compile_definitions(wolff_planar2 PUBLIC HAVE_GLUT)
   target_compile_definitions(wolff_heisenberg PUBLIC HAVE_GLUT)
 endif()
 
diff --git a/lib/cluster.h b/lib/cluster.h
index f948586..f3271b0 100644
--- a/lib/cluster.h
+++ b/lib/cluster.h
@@ -12,45 +12,45 @@
 #include "graph.h"
 
 template <class R_t, class X_t>
-void flip_cluster(state_t <R_t, X_t> *state, v_t v0, R_t r, gsl_rng *rand) {
+void flip_cluster(state_t<R_t, X_t>& s, v_t v0, const R_t& r, gsl_rng *rand) {
   v_t nv = 0;
 
   std::stack<v_t> stack;
   stack.push(v0);
 
-  std::vector<bool> marks(state->g.nv, false);
+  std::vector<bool> marks(s.g.nv, false);
 
   while (!stack.empty()) {
     v_t v = stack.top();
     stack.pop();
 
-    if (!marks[v]) {
+    if (!marks[v]) { // don't reprocess anyone we've already visited!
       X_t si_old, si_new;
       R_t R_old, R_new;
 
-      R_old = state->R;
+      R_old = s.R;
       marks[v] = true;
 
-      bool v_is_ghost = (v == state->nv);
+      bool v_is_ghost = (v == s.nv); // ghost site has the last index
 
       if (v_is_ghost) {
-        R_new = r.act(R_old);
+        R_new = r.act(R_old); // if we are, then we're moving the transformation
       } else {
-        si_old = state->spins[v];
-        si_new = r.act(si_old);
+        si_old = s.spins[v];
+        si_new = r.act(si_old); // otherwise, we're moving the spin at our site
       }
 
-      for (const v_t &vn : state->g.v_adj[v]) {
+      for (const v_t &vn : s.g.v_adj[v]) {
         X_t sj;
-        bool vn_is_ghost = (vn == state->nv);
+        bool vn_is_ghost = (vn == s.nv); // any of our neighbors could be the ghost
 
         if (!vn_is_ghost) {
-          sj = state->spins[vn];
+          sj = s.spins[vn];
         }
 
         double prob;
 
-        if (v_is_ghost || vn_is_ghost) {
+        if (v_is_ghost || vn_is_ghost) { // if this is a ghost-involved bond...
           X_t rs_old, rs_new;
           v_t non_ghost;
           if (vn_is_ghost) {
@@ -63,51 +63,54 @@ void flip_cluster(state_t <R_t, X_t> *state, v_t v0, R_t r, gsl_rng *rand) {
             non_ghost = vn;
           }
 
-          double dE = state->H(rs_old) - state->H(rs_new);
+          double dE = s.H(rs_old) - s.H(rs_new);
+
 #ifdef FINITE_STATES
           prob = H_probs[state_to_ind(rs_old)][state_to_ind(rs_new)];
 #else
-          prob = 1.0 - exp(-dE / state->T);
+          prob = 1.0 - exp(-dE / s.T);
 #endif
 
-          state->M -= rs_old;
-          state->M += rs_new;
+          s.M -= rs_old;
+          s.M += rs_new;
 
-          state->E += dE;
+          s.E += dE;
 
-          for (D_t i = 0; i < state->D; i++) {
-            L_t x = (non_ghost / (v_t)pow(state->L, state->D - i - 1)) % state->L;
+          for (D_t i = 0; i < s.D; i++) {
+            L_t x = (non_ghost / (v_t)pow(s.L, s.D - i - 1)) % s.L;
 
-            state->ReF[i] -= rs_old * state->precomputed_cos[x];
-            state->ReF[i] += rs_new * state->precomputed_cos[x];
+            s.ReF[i] -= rs_old * s.precomputed_cos[x];
+            s.ReF[i] += rs_new * s.precomputed_cos[x];
 
-            state->ImF[i] -= rs_old * state->precomputed_sin[x];
-            state->ImF[i] += rs_new * state->precomputed_sin[x];
+            s.ImF[i] -= rs_old * s.precomputed_sin[x];
+            s.ImF[i] += rs_new * s.precomputed_sin[x];
           }
-        } else {
-          double dE = state->J(si_old, sj) - state->J(si_new, sj);
+        } else { // otherwise, we're at a perfectly normal bond!
+          double dE = s.J(si_old, sj) - s.J(si_new, sj);
+
 #ifdef FINITE_STATES
           prob = J_probs[state_to_ind(si_old)][state_to_ind(si_new)][state_to_ind(sj)];
 #else
-          prob = 1.0 - exp(-dE / state->T);
+          prob = 1.0 - exp(-dE / s.T);
 #endif
-          state->E += dE;
+
+          s.E += dE;
         }
 
-        if (gsl_rng_uniform(rand) < prob) { // and with probability...
+        if (gsl_rng_uniform(rand) < prob) {
           stack.push(vn); // push the neighboring vertex to the stack
         }
       }
 
       if (v_is_ghost) {
-        state->R = R_new;
+        s.R = R_new;
       } else {
-        state->spins[v] = si_new;
+        s.spins[v] = si_new;
         nv++;
       }
     }
   }
 
-  state->last_cluster_size = nv;
+  s.last_cluster_size = nv;
 }
 
diff --git a/lib/correlation.h b/lib/correlation.h
index 49c6ff2..23b1bd9 100644
--- a/lib/correlation.h
+++ b/lib/correlation.h
@@ -7,13 +7,13 @@
 #include <fftw3.h>
 
 template <class R_t, class X_t>
-double correlation_length(const state_t <R_t, X_t> *s) {
+double correlation_length(const state_t <R_t, X_t>& s) {
   double total = 0;
 
-  for (D_t j = 0; j < s->D; j++) {
-    total += norm_squared(s->ReF[j]) + norm_squared(s->ReF[j]);
+  for (D_t j = 0; j < s.D; j++) {
+    total += norm_squared(s.ReF[j]) + norm_squared(s.ReF[j]);
   }
 
-  return total / s->D;
+  return total / s.D;
 }
 
diff --git a/lib/measure.h b/lib/measure.h
index 8082dd2..2c5ffb7 100644
--- a/lib/measure.h
+++ b/lib/measure.h
@@ -29,17 +29,17 @@ FILE **measure_setup_files(unsigned char flags, unsigned long timestamp) {
 }
 
 template <class R_t, class X_t>
-std::function <void(const state_t <R_t, X_t> *)> measure_function_write_files(unsigned char flags, FILE **files, std::function <void(const state_t <R_t, X_t> *)> other_f) {
-  return [=] (const state_t <R_t, X_t> *s) {
+std::function <void(const state_t <R_t, X_t>&)> measure_function_write_files(unsigned char flags, FILE **files, std::function <void(const state_t <R_t, X_t>&)> other_f) {
+  return [=] (const state_t <R_t, X_t>& s) {
     if (flags & measurement_energy) {
-      float smaller_E = (float)s->E;
+      float smaller_E = (float)s.E;
       fwrite(&smaller_E, sizeof(float), 1, files[0]);
     }
     if (flags & measurement_clusterSize) {
-      fwrite(&(s->last_cluster_size), sizeof(uint32_t), 1, files[1]);
+      fwrite(&(s.last_cluster_size), sizeof(uint32_t), 1, files[1]);
     }
     if (flags & measurement_magnetization) {
-      write_magnetization(s->M, files[2]);
+      write_magnetization(s.M, files[2]);
     }
     if (flags & measurement_fourierZero) {
       float smaller_X = (float)correlation_length(s);
diff --git a/lib/wolff.h b/lib/wolff.h
index a4a663c..498f7f3 100644
--- a/lib/wolff.h
+++ b/lib/wolff.h
@@ -3,18 +3,18 @@
 #include "state.h"
 
 template <class R_t, class X_t>
-void wolff(count_t N, state_t <R_t, X_t> *s, std::function <R_t(gsl_rng *, X_t s0)> gen_R, std::function <void(const state_t <R_t, X_t> *)> measurements, gsl_rng *r, bool silent) {
+void wolff(count_t N, state_t <R_t, X_t>& s, std::function <R_t(gsl_rng *, X_t s0)> gen_R, std::function <void(const state_t <R_t, X_t>&)> measurements, gsl_rng *r, bool silent) {
 
 #ifdef FINITE_STATES
-  initialize_probs(s->J, s->H, s->T);
+  initialize_probs(s.J, s.H, s.T);
 #endif
 
   if (!silent) printf("\n");
   for (count_t steps = 0; steps < N; steps++) {
-    if (!silent) printf("\033[F\033[JWOLFF: step %" PRIu64 " / %" PRIu64 ": E = %.2f, S = %" PRIv "\n", steps, N, s->E, s->last_cluster_size);
+    if (!silent) printf("\033[F\033[JWOLFF: step %" PRIu64 " / %" PRIu64 ": E = %.2f, S = %" PRIv "\n", steps, N, s.E, s.last_cluster_size);
 
-    v_t v0 = gsl_rng_uniform_int(r, s->nv);
-    R_t step = gen_R(r, s->spins[v0]);
+    v_t v0 = gsl_rng_uniform_int(r, s.nv);
+    R_t step = gen_R(r, s.spins[v0]);
     flip_cluster <R_t, X_t> (s, v0, step, r);
 
     measurements(s);
@@ -23,7 +23,7 @@ void wolff(count_t N, state_t <R_t, X_t> *s, std::function <R_t(gsl_rng *, X_t s
   if (!silent) {
     printf("\033[F\033[J");
   }
-  printf("WOLFF: step %" PRIu64 " / %" PRIu64 ": E = %.2f, S = %" PRIv "\n", N, N, s->E, s->last_cluster_size);
+  printf("WOLFF: step %" PRIu64 " / %" PRIu64 ": E = %.2f, S = %" PRIv "\n", N, N, s.E, s.last_cluster_size);
 
 }
 
diff --git a/lib/z2.h b/lib/z2.h
index fd4722e..a18d740 100644
--- a/lib/z2.h
+++ b/lib/z2.h
@@ -25,7 +25,7 @@ class z2_t {
 
   z2_t(bool x) : x(x) {}
 
-  ising_t act(const ising_t& s) {
+  ising_t act(const ising_t& s) const {
     if (x) {
       return ising_t(!s.x);
     } else {
@@ -33,7 +33,7 @@ class z2_t {
     }
   }
 
-  z2_t act(const z2_t& r) {
+  z2_t act(const z2_t& r) const {
     if (x) {
       return z2_t(!r.x);
     } else {
@@ -41,11 +41,11 @@ class z2_t {
     }
   }
 
-  ising_t act_inverse(const ising_t& s) {
+  ising_t act_inverse(const ising_t& s) const {
     return this->act(s);
   }
 
-  z2_t act_inverse(const z2_t& r) {
+  z2_t act_inverse(const z2_t& r) const {
     return this->act(r);
   }
 };
diff --git a/src/wolff_O2.cpp b/src/wolff_O2.cpp
deleted file mode 100644
index 63ca0a7..0000000
--- a/src/wolff_O2.cpp
+++ /dev/null
@@ -1,278 +0,0 @@
-
-#include <getopt.h>
-#include <stdio.h>
-
-#ifdef HAVE_GLUT
-#include <GL/glut.h>
-#endif
-
-#include <circle_group.h>
-#include <angle.h>
-
-#include <wolff.h>
-#include <measure.h>
-#include <colors.h>
-#include <rand.h>
-
-typedef circle_group_t orthogonal_R_t;
-typedef angle_t vector_R_t;
-typedef state_t <orthogonal_R_t, vector_R_t> On_t;
-
-double H_modulated(vector_R_t v, int order, double mag) {
-  return mag * cos(order * v.x);
-}
-
-double theta(double *v) {
-  double x = v[0];
-  double y = v[1];
-
-  if (x == 0) { 
-    if (y >= 0) {
-      return M_PI / 2;
-    } else {
-      return - M_PI / 2;
-    }
-  } else {
-    double val = atan(y / x);
-
-    if (x < 0.0 && y > 0.0) {
-      return M_PI + val;
-    } else if ( x < 0.0 && y < 0.0 ) {
-      return - M_PI + val;
-    } else {
-      return val;
-    }
-  }
-}
-
-int main(int argc, char *argv[]) {
-
-  count_t N = (count_t)1e7;
-
-  D_t D = 2;
-  L_t L = 128;
-  double T = 2.26918531421;
-  double *H_vec = (double *)calloc(MAX_Q, sizeof(double));
-
-  bool silent = false;
-  bool use_pert = false;
-  bool N_is_sweeps = false;
-  bool draw = false;
-  unsigned int window_size = 512;
-
-  bool modulated_field = false;
-  unsigned int order = 1;
-
-  int opt;
-  q_t H_ind = 0;
-  double epsilon = 1;
-
-//  unsigned char measurement_flags = measurement_energy | measurement_clusterSize;
-
-  unsigned char measurement_flags = 0;
-
-  while ((opt = getopt(argc, argv, "N:D:L:T:H:spe:mo:M:Sdw:")) != -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_vec[H_ind] = atof(optarg);
-      H_ind++;
-      break;
-    case 's': // don't print anything during simulation. speeds up slightly
-      silent = true;
-      break;
-    case 'p':
-      use_pert = true;
-      break;
-    case 'e':
-      epsilon = atof(optarg);
-      break;
-    case 'm':
-      modulated_field = true;
-      break;
-    case 'M':
-      measurement_flags ^= 1 << atoi(optarg);
-      break;
-    case 'o':
-      order = atoi(optarg);
-      break;
-    case 'S':
-      N_is_sweeps = 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);
-    }
-  }
-
-  unsigned long timestamp;
-
-  {
-    struct timespec spec;
-    clock_gettime(CLOCK_REALTIME, &spec);
-    timestamp = spec.tv_sec*1000000000LL + spec.tv_nsec;
-  }
-
-  const char *pert_type;
-
-  std::function <orthogonal_R_t(gsl_rng *, vector_R_t)> gen_R;
-
-  if (use_pert) {
-    gen_R = [=] (gsl_rng *r, const angle_t& t) -> circle_group_t {
-      circle_group_t rot;
-      rot.is_reflection = true;
-
-      unsigned int x = gsl_rng_uniform_int(r, order);
-      double amount = epsilon * gsl_ran_ugaussian(r);
-
-      rot.x = fmod(2 * M_PI * (1.0 + (double)x / (double)order + amount), 2 * M_PI);
-
-      return rot;
-    };
-    pert_type = "PERTURB";
-  } else {
-    gen_R = [=] (gsl_rng *r, const angle_t& t) -> circle_group_t {
-      circle_group_t rot;
-      rot.is_reflection = true;
-      rot.x = 2 * M_PI * gsl_rng_uniform(r);
-
-      return rot;
-    };
-    pert_type = "UNIFORM";
-  }
-
-  FILE *outfile_info = fopen("wolff_metadata.txt", "a");
-
-  fprintf(outfile_info, "<| \"ID\" -> %lu, \"MODEL\" -> \"%s\", \"q\" -> %d, \"D\" -> %" PRID ", \"L\" -> %" PRIL ", \"NV\" -> %" PRIv ", \"NE\" -> %" PRIv ", \"T\" -> %.15f, \"FIELD_TYPE\" -> ", timestamp, ON_strings[2], 2, D, L, (v_t)pow(L, D), D * (v_t)pow(L, D), T);
-  if (modulated_field) {
-    fprintf(outfile_info, "\"MODULATED\", \"ORDER\" -> %d, \"H\" -> %.15f, ", order, H_vec[0]);
-  } else {
-    fprintf(outfile_info, "\"VECTOR\", \"H\" -> {");
-    for (q_t i = 0; i < 2; i++) {
-      fprintf(outfile_info, "%.15f", H_vec[i]);
-      if (i < 2 - 1) {
-        fprintf(outfile_info, ", ");
-      }
-    }
-    fprintf(outfile_info, "}, ");
-  }
-
-  fprintf(outfile_info, "\"GENERATOR\" -> \"%s\"", pert_type);
-
-  if (use_pert) {
-    fprintf(outfile_info, ", \"EPS\" -> %g", epsilon);
-  }
-
-  fprintf(outfile_info, " |>\n");
-
-  fclose(outfile_info);
-
-  FILE **outfiles = measure_setup_files(measurement_flags, timestamp);
-
-  std::function <void(const On_t *)> other_f;
-  uint64_t sum_of_clusterSize = 0;
-
-  if (N_is_sweeps) {
-    other_f = [&] (const On_t *s) {
-      sum_of_clusterSize += s->last_cluster_size;
-    };
-  } else if (draw) {
-#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);
-
-    other_f = [&] (const On_t *s) {
-      glClear(GL_COLOR_BUFFER_BIT);
-      for (v_t i = 0; i < pow(L, 2); i++) {
-        vector_R_t v_tmp = s->R.act_inverse(s->spins[i]);
-        double saturation = 0.7;
-        double value = 0.9;
-        double chroma = saturation * value;
-        glColor3f(chroma * hue_to_R(v_tmp.x) + (value - chroma), chroma * hue_to_G(v_tmp.x) + (value - chroma), chroma * hue_to_B(v_tmp.x) + (value - chroma));
-        glRecti(i / L, i % L, (i / L) + 1, (i % L) + 1);
-      }
-      glFlush();
-    };
-#endif
-  } else {
-    other_f = [] (const On_t *s) {};
-  }
-
-  std::function <void(const On_t *)> measurements = measure_function_write_files(measurement_flags, outfiles, other_f);
-
-  std::function <double(const angle_t&, const angle_t&)> J = [] (const angle_t& t1, const angle_t& t2) -> double {
-    return cos(t1.x - t2.x);
-  };
-
-  std::function <double(const angle_t &)> H;
-
-  if (modulated_field) {
-    H = [=] (const angle_t& t) -> double {
-      return H_vec[0] * cos(order * t.x);
-    };
-  } else {
-    double mag = 0;
-    for (q_t i = 0; i < 2; i++) {
-      mag += pow(H_vec[i], 2);
-    }
-    mag = sqrt(mag);
-    double t0 = theta(H_vec);
-    H = [=] (const angle_t& t) -> double {
-      return mag * cos(t0 + t.x);
-    };
-  }
-
-  // initialize random number generator
-  gsl_rng *r = gsl_rng_alloc(gsl_rng_taus2);
-  gsl_rng_set(r, rand_seed());
-
-  state_t <orthogonal_R_t, vector_R_t> s(D, L, T, J, H);
-
-  if (N_is_sweeps) {
-    count_t N_rounds = 0;
-    printf("\n");
-    while (sum_of_clusterSize < N * s.nv) {
-      printf("\033[F\033[J\033[F\033[JWOLFF: sweep %" PRIu64 " / %" PRIu64 ": E = %.2f, S = %" PRIv "\n", (count_t)((double)sum_of_clusterSize / (double)s.nv), N, s.E, s.last_cluster_size);
-      wolff <orthogonal_R_t, vector_R_t> (N, &s, gen_R, measurements, r, silent);
-      N_rounds++;
-    }
-    printf("\033[F\033[J\033[F\033[JWOLFF: sweep %" PRIu64 " / %" PRIu64 ": E = %.2f, S = %" PRIv "\n\n", (count_t)((double)sum_of_clusterSize / (double)s.nv), N, s.E, s.last_cluster_size);
-  } else {
-    wolff <orthogonal_R_t, vector_R_t> (N, &s, gen_R, measurements, r, silent);
-  }
-
-  measure_free_files(measurement_flags, outfiles);
-  free(H_vec);
-  gsl_rng_free(r);
-
-  return 0;
-}
-
diff --git a/src/wolff_On.cpp b/src/wolff_On.cpp
index cbde498..3fa5840 100644
--- a/src/wolff_On.cpp
+++ b/src/wolff_On.cpp
@@ -167,12 +167,12 @@ int main(int argc, char *argv[]) {
 
   FILE **outfiles = measure_setup_files(measurement_flags, timestamp);
 
-  std::function <void(const On_t *)> other_f;
+  std::function <void(const On_t&)> other_f;
   uint64_t sum_of_clusterSize = 0;
 
   if (N_is_sweeps) {
-    other_f = [&] (const On_t *s) {
-      sum_of_clusterSize += s->last_cluster_size;
+    other_f = [&] (const On_t& s) {
+      sum_of_clusterSize += s.last_cluster_size;
     };
   } else if (draw) {
 #ifdef HAVE_GLUT
@@ -186,10 +186,10 @@ int main(int argc, char *argv[]) {
     glLoadIdentity();
     gluOrtho2D(0.0, L, 0.0, L);
 
-    other_f = [&] (const On_t *s) {
+    other_f = [&] (const On_t& s) {
       glClear(GL_COLOR_BUFFER_BIT);
       for (v_t i = 0; i < pow(L, 2); i++) {
-        vector_R_t v_tmp = s->R.act_inverse(s->spins[i]);
+        vector_R_t v_tmp = s.R.act_inverse(s.spins[i]);
         double thetai = fmod(2 * M_PI + theta(v_tmp), 2 * M_PI);
         double saturation = 0.7;
         double value = 0.9;
@@ -201,10 +201,10 @@ int main(int argc, char *argv[]) {
     };
 #endif
   } else {
-    other_f = [] (const On_t *s) {};
+    other_f = [] (const On_t& s) {};
   }
 
-  std::function <void(const On_t *)> measurements = measure_function_write_files(measurement_flags, outfiles, other_f);
+  std::function <void(const On_t&)> measurements = measure_function_write_files(measurement_flags, outfiles, other_f);
 
   std::function <double(const vector_R_t&)> H;
 
@@ -225,12 +225,12 @@ int main(int argc, char *argv[]) {
     printf("\n");
     while (sum_of_clusterSize < N * s.nv) {
       printf("\033[F\033[J\033[F\033[JWOLFF: sweep %" PRIu64 " / %" PRIu64 ": E = %.2f, S = %" PRIv "\n", (count_t)((double)sum_of_clusterSize / (double)s.nv), N, s.E, s.last_cluster_size);
-      wolff <orthogonal_R_t, vector_R_t> (N, &s, gen_R, measurements, r, silent);
+      wolff <orthogonal_R_t, vector_R_t> (N, s, gen_R, measurements, r, silent);
       N_rounds++;
     }
     printf("\033[F\033[J\033[F\033[JWOLFF: sweep %" PRIu64 " / %" PRIu64 ": E = %.2f, S = %" PRIv "\n\n", (count_t)((double)sum_of_clusterSize / (double)s.nv), N, s.E, s.last_cluster_size);
   } else {
-    wolff <orthogonal_R_t, vector_R_t> (N, &s, gen_R, measurements, r, silent);
+    wolff <orthogonal_R_t, vector_R_t> (N, s, gen_R, measurements, r, silent);
   }
 
   measure_free_files(measurement_flags, outfiles);
diff --git a/src/wolff_cgm.cpp b/src/wolff_cgm.cpp
index ec3ae36..ce91bf2 100644
--- a/src/wolff_cgm.cpp
+++ b/src/wolff_cgm.cpp
@@ -100,13 +100,13 @@ int main(int argc, char *argv[]) {
   };
 
   // define function that updates any number of measurements
-  std::function <void(const sim_t *)> measurement;
+  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;
+    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
@@ -122,13 +122,13 @@ int main(int argc, char *argv[]) {
     glLoadIdentity();
     gluOrtho2D(0.0, L, 0.0, L);
 
-    measurement = [&] (const sim_t *s) {
-      average_M += (double)s->M / (double)N / (double)s->nv;
+    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;
+        double cur_h = (s.R.act_inverse(s.spins[i])).x;
         if (cur_h < min_h) {
           min_h = cur_h;
         }
@@ -138,7 +138,7 @@ int main(int argc, char *argv[]) {
       }
 
       for (v_t i = 0; i < pow(L, 2); i++) {
-        double cur_h = (s->R.act_inverse(s->spins[i])).x;
+        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);
@@ -149,7 +149,7 @@ int main(int argc, char *argv[]) {
   }
 
   // run wolff for N cluster flips
-  wolff(N, &s, gen_R, measurement, r, silent);
+  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);
diff --git a/src/wolff_clock.cpp b/src/wolff_clock.cpp
index 376eaec..3dec284 100644
--- a/src/wolff_clock.cpp
+++ b/src/wolff_clock.cpp
@@ -101,13 +101,13 @@ int main(int argc, char *argv[]) {
   };
 
   // define function that updates any number of measurements
-  std::function <void(const sim_t *)> measurement;
+  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[0] / (double)N / (double)s->nv;
+    measurement = [&] (const sim_t& s) {
+      average_M += (double)s.M[0] / (double)N / (double)s.nv;
     };
   } else {
     // a more complex example: measure the average magnetization, and draw the spin configuration to the screen
@@ -123,11 +123,11 @@ int main(int argc, char *argv[]) {
     glLoadIdentity();
     gluOrtho2D(0.0, L, 0.0, L);
 
-    measurement = [&] (const sim_t *s) {
-      average_M += (double)s->M[0] / (double)N / (double)s->nv;
+    measurement = [&] (const sim_t& s) {
+      average_M += (double)s.M[0] / (double)N / (double)s.nv;
       glClear(GL_COLOR_BUFFER_BIT);
       for (v_t i = 0; i < pow(L, 2); i++) {
-        potts_t<POTTSQ> tmp_s = s->R.act_inverse(s->spins[i]);
+        potts_t<POTTSQ> tmp_s = s.R.act_inverse(s.spins[i]);
         glColor3f(hue_to_R(tmp_s.x * 2 * M_PI / POTTSQ), hue_to_G(tmp_s.x * 2 * M_PI / POTTSQ), hue_to_B(tmp_s.x * 2 * M_PI / POTTSQ));
         glRecti(i / L, i % L, (i / L) + 1, (i % L) + 1);
       }
@@ -137,7 +137,7 @@ int main(int argc, char *argv[]) {
   }
 
   // run wolff for N cluster flips
-  wolff(N, &s, gen_R, measurement, r, silent);
+  wolff(N, s, gen_R, measurement, r, silent);
 
   // tell us what we found!
   printf("%" PRIcount " %d-Potts runs completed. D = %" PRID ", L = %" PRIL ", T = %g, H = %g, <M> = %g\n", N, POTTSQ, D, L, T, H_vec[0], average_M);
diff --git a/src/wolff_dgm.cpp b/src/wolff_dgm.cpp
index d00cae5..8667fb5 100644
--- a/src/wolff_dgm.cpp
+++ b/src/wolff_dgm.cpp
@@ -105,13 +105,13 @@ int main(int argc, char *argv[]) {
   };
 
   // define function that updates any number of measurements
-  std::function <void(const sim_t *)> measurement;
+  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;
+    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
@@ -127,13 +127,13 @@ int main(int argc, char *argv[]) {
     glLoadIdentity();
     gluOrtho2D(0.0, L, 0.0, L);
 
-    measurement = [&] (const sim_t *s) {
-      average_M += (double)s->M / (double)N / (double)s->nv;
+    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;
+        int64_t cur_h = (s.R.act_inverse(s.spins[i])).x;
         if (cur_h < min_h) {
           min_h = cur_h;
         }
@@ -143,7 +143,7 @@ int main(int argc, char *argv[]) {
       }
 
       for (v_t i = 0; i < pow(L, 2); i++) {
-        int64_t cur_h = (s->R.act_inverse(s->spins[i])).x;
+        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);
@@ -154,7 +154,7 @@ int main(int argc, char *argv[]) {
   }
 
   // run wolff for N cluster flips
-  wolff(N, &s, gen_R, measurement, r, silent);
+  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);
diff --git a/src/wolff_ising.cpp b/src/wolff_ising.cpp
index 0c9485d..24bf74c 100644
--- a/src/wolff_ising.cpp
+++ b/src/wolff_ising.cpp
@@ -126,12 +126,12 @@ int main(int argc, char *argv[]) {
 
   FILE **outfiles = measure_setup_files(measurement_flags, timestamp);
 
-  std::function <void(const state_t<z2_t, ising_t> *)> other_f;
+  std::function <void(const state_t<z2_t, ising_t>&)> other_f;
   uint64_t sum_of_clusterSize = 0;
 
   if (N_is_sweeps) {
-    other_f = [&] (const state_t<z2_t, ising_t> *s) {
-      sum_of_clusterSize += s->last_cluster_size;
+    other_f = [&] (const state_t<z2_t, ising_t>& s) {
+      sum_of_clusterSize += s.last_cluster_size;
     };
   } else if (draw) {
 #ifdef HAVE_GLUT
@@ -145,24 +145,24 @@ int main(int argc, char *argv[]) {
     glLoadIdentity();
     gluOrtho2D(0.0, L, 0.0, L);
 
-    other_f = [] (const state_t <z2_t, ising_t> *s) {
+    other_f = [] (const state_t <z2_t, ising_t>& s) {
       glClear(GL_COLOR_BUFFER_BIT);
-      for (v_t i = 0; i < pow(s->L, 2); i++) {
-        if (s->spins[i].x == s->R.x) {
+      for (v_t i = 0; i < pow(s.L, 2); i++) {
+        if (s.spins[i].x == s.R.x) {
           glColor3f(0.0, 0.0, 0.0);
         } else {
           glColor3f(1.0, 1.0, 1.0);
         }
-        glRecti(i / s->L, i % s->L, (i / s->L) + 1, (i % s->L) + 1);
+        glRecti(i / s.L, i % s.L, (i / s.L) + 1, (i % s.L) + 1);
       }
       glFlush();
     };
 #endif
   } else {
-    other_f = [] (const state_t<z2_t, ising_t> *s) {};
+    other_f = [] (const state_t<z2_t, ising_t>& s) {};
   }
 
-  std::function <void(const state_t<z2_t, ising_t> *)> measurements = measure_function_write_files(measurement_flags, outfiles, other_f);
+  std::function <void(const state_t<z2_t, ising_t>&)> measurements = measure_function_write_files(measurement_flags, outfiles, other_f);
 
   // add line to metadata file with run info
   {
@@ -179,12 +179,12 @@ int main(int argc, char *argv[]) {
     printf("\n");
     while (sum_of_clusterSize < N * s.nv) {
       printf("\033[F\033[J\033[F\033[JWOLFF: sweep %" PRIu64 " / %" PRIu64 ": E = %.2f, S = %" PRIv "\n", (count_t)((double)sum_of_clusterSize / (double)s.nv), N, s.E, s.last_cluster_size);
-      wolff(N, &s, gen_R, measurements, r, silent);
+      wolff(N, s, gen_R, measurements, r, silent);
       N_rounds++;
     }
     printf("\033[F\033[J\033[F\033[JWOLFF: sweep %" PRIu64 " / %" PRIu64 ": E = %.2f, S = %" PRIv "\n\n", (count_t)((double)sum_of_clusterSize / (double)s.nv), N, s.E, s.last_cluster_size);
   } else {
-    wolff(N, &s, gen_R, measurements, r, silent);
+    wolff(N, s, gen_R, measurements, r, silent);
   }
 
   // free the random number generator
diff --git a/src/wolff_potts.cpp b/src/wolff_potts.cpp
index 2bc306b..9fe3ffe 100644
--- a/src/wolff_potts.cpp
+++ b/src/wolff_potts.cpp
@@ -135,12 +135,12 @@ int main(int argc, char *argv[]) {
 
   FILE **outfiles = measure_setup_files(measurement_flags, timestamp);
 
-  std::function <void(const sim_t *)> other_f;
+  std::function <void(const sim_t&)> other_f;
   uint64_t sum_of_clusterSize = 0;
 
   if (N_is_sweeps) {
-    other_f = [&] (const sim_t *s) {
-      sum_of_clusterSize += s->last_cluster_size;
+    other_f = [&] (const sim_t& s) {
+      sum_of_clusterSize += s.last_cluster_size;
     };
   } else if (draw) {
 #ifdef HAVE_GLUT
@@ -154,21 +154,21 @@ int main(int argc, char *argv[]) {
     glLoadIdentity();
     gluOrtho2D(0.0, L, 0.0, L);
 
-    other_f = [] (const sim_t *s) {
+    other_f = [] (const sim_t& s) {
       glClear(GL_COLOR_BUFFER_BIT);
-      for (v_t i = 0; i < pow(s->L, 2); i++) {
-        potts_t<POTTSQ> tmp_s = s->R.act_inverse(s->spins[i]);
+      for (v_t i = 0; i < pow(s.L, 2); i++) {
+        potts_t<POTTSQ> tmp_s = s.R.act_inverse(s.spins[i]);
         glColor3f(hue_to_R(tmp_s.x * 2 * M_PI / POTTSQ), hue_to_G(tmp_s.x * 2 * M_PI / POTTSQ), hue_to_B(tmp_s.x * 2 * M_PI / POTTSQ));
-        glRecti(i / s->L, i % s->L, (i / s->L) + 1, (i % s->L) + 1);
+        glRecti(i / s.L, i % s.L, (i / s.L) + 1, (i % s.L) + 1);
       }
       glFlush();
     };
 #endif
   } else {
-    other_f = [] (const sim_t *s) {};
+    other_f = [] (const sim_t& s) {};
   }
 
-  std::function <void(const sim_t *)> measurements = measure_function_write_files(measurement_flags, outfiles, other_f);
+  std::function <void(const sim_t&)> measurements = measure_function_write_files(measurement_flags, outfiles, other_f);
 
   // add line to metadata file with run info
   {
@@ -194,12 +194,12 @@ int main(int argc, char *argv[]) {
     printf("\n");
     while (sum_of_clusterSize < N * s.nv) {
       printf("\033[F\033[J\033[F\033[JWOLFF: sweep %" PRIu64 " / %" PRIu64 ": E = %.2f, S = %" PRIv "\n", (count_t)((double)sum_of_clusterSize / (double)s.nv), N, s.E, s.last_cluster_size);
-      wolff(N, &s, gen_R, measurements, r, silent);
+      wolff(N, s, gen_R, measurements, r, silent);
       N_rounds++;
     }
     printf("\033[F\033[J\033[F\033[JWOLFF: sweep %" PRIu64 " / %" PRIu64 ": E = %.2f, S = %" PRIv "\n\n", (count_t)((double)sum_of_clusterSize / (double)s.nv), N, s.E, s.last_cluster_size);
   } else {
-    wolff(N, &s, gen_R, measurements, r, silent);
+    wolff(N, s, gen_R, measurements, r, silent);
   }
 
   // free the random number generator