1 files changed, 142 insertions, 0 deletions
diff --git a/models/correlations/tune_rho.c b/models/correlations/tune_rho.c
new file mode 100644
index 0000000..4495b0e
--- /dev/null
+++ b/models/correlations/tune_rho.c
@@ -0,0 +1,142 @@
+/**
+ *
+ * Tune the Spearman's \rho correlation coefficient between two rankings
+ * given as input, using a simulated-anneling procedure
+ *
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <strings.h>
+#include <time.h>
+
+#include "rank_utils.h"
+
+//void select_pairing(int *pairing, int N, int argc, char *argv[]){
+//
+//  if (argc < 7 || !strncasecmp("rnd", argv[6], 3)){
+//    init_pairing_random(pairing, N);
+//  }
+//  else if (!strncasecmp("nat", argv[6], 3)){
+//    init_pairing_natural(pairing, N);
+//  }
+//  else if (!strncasecmp("inv", argv[6], 3)){
+//    init_pairing_inverse(pairing, N);
+//  }
+//  else{
+//    printf ("Pairing strategy \"%s\" unknown!!! Exiting...\n", argv[6]);
+//    exit(1);
+//  }
+//
+//}
+
+void tune_rho(double *R1, double *R2, int N, int *pairing, double eps, 
+              double beta, double rho_target){
+  
+  double act_rho, test_rho, F, F_new;
+  double val, prob;
+  int *new_pairing;
+  int p1, p2, tmp_val;
+  int tot;
+ 
+  new_pairing = malloc(N * sizeof(int));
+  copy_pairing(pairing, new_pairing, N);
+  
+  act_rho = compute_rho(R1, R2, N, pairing);
+  
+  F = fabs(act_rho - rho_target);
+  
+  //fprintf("%f %f %f %f %f\n", eps, beta, rho_target, act_rho, F);
+  
+  tot = 0;
+  while (F > eps){
+    /* sample two positions of "pairing" and shuffle them in "new_pairing" */
+    p1 = rand() % N;
+    p2 = rand() % N;
+    while (p2 == p1){
+      p2 = rand() % N;
+    }
+    tmp_val = new_pairing[p1];
+    new_pairing[p1] = new_pairing[p2];
+    new_pairing[p2] = tmp_val;
+    test_rho = compute_rho(R1, R2, N, new_pairing);
+    F_new = fabs(test_rho - rho_target);
+    if (F_new < F){/* Accept this swap with probability 1 */
+      tmp_val = pairing[p1];
+      pairing[p1] = pairing[p2];
+      pairing[p2] = tmp_val;
+      act_rho = test_rho;
+    }
+    else{/* Accept the swap with a certain probability */
+      val = 1.0 * rand() / RAND_MAX;
+
+      //prob = pow(fabs(F - F_new)/(F+F_new), beta);
+      prob = exp(-(F_new - F)/beta);
+      //fprintf(stderr, "-- %f\n", prob);
+      if (val < prob){ /* Accept the swap */
+        tmp_val = pairing[p1];
+        pairing[p1] = pairing[p2];
+        pairing[p2] = tmp_val;
+        act_rho = test_rho;
+      }
+      else{ /* Rollback the swap */
+        tmp_val = new_pairing[p1];
+        new_pairing[p1] = new_pairing[p2];
+        new_pairing[p2] = tmp_val;
+      }
+      
+    }
+    F = fabs(act_rho - rho_target);
+    if (tot % 200 == 0){
+      fprintf(stderr, "%d %g\n", tot, act_rho);
+    }
+    tot += 1;
+  }
+}
+
+
+
+
+int main (int argc, char *argv[]){
+
+  int N1, N2;
+  double *R1 = NULL;
+  double *R2 = NULL;
+  double eps, beta, rho, rho_target;
+  
+  int *pairing = NULL;
+
+  srand(time(NULL));
+  
+  if (argc < 6){
+    printf("Usage: %s <rank1> <rank2> <rho> <eps> <beta> [RND|NAT|INV]\n", argv[0]);
+    exit(1);
+  }
+  
+  rho_target = atof(argv[3]);
+  eps = atof(argv[4]);
+  beta = atof(argv[5]);
+  
+  load_ranking(argv[1], &N1, &R1);
+  load_ranking(argv[2], &N2, &R2);
+  
+  if (N1 != N2){
+    printf("Error!!!! The two files must have the same number of lines!!!! Exiting...\n");
+    exit(1);
+  }
+  
+  pairing = malloc(N1 * sizeof(int));
+
+  select_pairing(pairing, N1, argc, argv, 6);
+  
+  rho = compute_rho(R1, R2, N1, pairing);
+  
+  fprintf(stderr, "%g\n", rho);
+  
+  tune_rho(R1, R2, N1, pairing, eps, beta, rho_target);
+
+  dump_pairing(pairing, N1);
+  
+}