1 files changed, 217 insertions, 0 deletions
diff --git a/structure/correlations/rank_utils.c b/structure/correlations/rank_utils.c
new file mode 100644
index 0000000..4b8ef41
--- /dev/null
+++ b/structure/correlations/rank_utils.c
@@ -0,0 +1,217 @@
+/**
+ *
+ * Some utility functions to be used with tune_rho, compute_rho and
+ * the like
+ *
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <string.h>
+#include <time.h>
+
+#include "rank_utils.h"
+
+void load_ranking(char *fname, int *N, double **R){
+  
+  char buff[256];
+  int size = 10;
+  FILE *f;
+  
+  if (*R == NULL){
+    *R = malloc(size * sizeof (double));
+  }
+  f = fopen(fname, "r");
+  if (!f){
+    printf("Unable to open file: %s!!! Exiting\n");
+    exit(1);
+  }
+  
+  *N = 0;
+ 
+  while (fgets(buff, 255, f)){
+    if (* N == size){
+      size += 10;
+      *R = realloc(*R, size * sizeof(double));
+    }
+    (*R)[*N] = atof(buff);
+    *N += 1;
+  }
+}
+
+double avg_array(double *v, int N){
+  
+  double sum = 0.0;
+  int i;
+  
+  for (i = 0; i < N; i ++){
+    sum += v[i];
+  }
+  return sum/N;
+}
+
+double compute_C(double *R1, double *R2, int N){
+  double mu1, mu2, sum1, sum2;
+
+  mu1 = avg_array(R1, N);
+  mu2 = avg_array(R2, N);
+  
+  sum1 = mu1 * N;
+  sum2 = mu2 * N;
+  
+  return N * mu1 * mu2 - mu2 * sum1 - mu1 * sum2;
+}
+
+
+double compute_D(double *R1, double *R2, int N){
+  
+  double mu1, mu2, s1, s2;
+  int i;
+
+  mu1 = avg_array(R1, N);
+  mu2 = avg_array(R1, N);
+  
+  s1 = s2 = 0.0;
+  
+  for (i=0 ; i < N; i ++){
+    s1 += pow((R1[i] - mu1), 2);
+    s2 += pow((R2[i] - mu2), 2);
+  }
+  
+  return sqrt(s1 * s2);
+}
+
+
+double compute_rho(double *R1, double *R2, int N, int *pairing){
+  
+  double rho = 0;
+  int i;
+  
+  for (i=0; i < N; i ++){
+    rho += R1[i] * R2[ pairing[i] ];
+  }
+
+  rho = (rho + compute_C(R1, R2, N))/ compute_D(R1, R2, N);
+  return rho;
+}
+
+void dump_ranking(double *R, int N){
+  int i;
+
+  for (i=0; i < N; i ++){
+    printf("%d: %f\n", i, R[i] );
+  }
+}
+
+
+void init_pairing_natural(int *pairing, int N){
+  int i;
+
+  for (i = 0; i< N; i ++){
+    pairing[i] = i;
+  }
+}
+
+void init_pairing_inverse(int *pairing, int N){
+  int i;
+
+  for (i = 0; i< N; i ++){
+    pairing[i] = N-i-1;
+  }
+}
+
+void select_pairing(int *pairing, int N, int argc, char *argv[], int pos){
+
+  if (argc < pos + 1 || !strncasecmp("rnd", argv[pos], 3)){
+    init_pairing_random(pairing, N);
+  }
+  else if (!strncasecmp("nat", argv[pos], 3)){
+    init_pairing_natural(pairing, N);
+  }
+  else if (!strncasecmp("inv", argv[pos], 3)){
+    init_pairing_inverse(pairing, N);
+  }
+  else{
+    printf ("Pairing strategy \"%s\" unknown!!! Exiting...\n", argv[pos]);
+    exit(1);
+  }
+
+}
+
+
+void shuffle_sequence(int *s, int N){
+  
+  int i, j, tmp;
+
+  for (i=N-1; i>=0; i--){
+    j = rand() % (i+1);
+    tmp = s[j];
+    s[j] = s[i];
+    s[i] = tmp;
+  }
+}
+
+
+
+void init_pairing_random(int *pairing, int N){
+
+  init_pairing_natural(pairing, N);
+  shuffle_sequence(pairing, N);
+
+}
+
+/* Loads a pairing from a file, in the format:
+ * 
+ * rank1 rank2
+ * ...........
+ */
+void load_pairing(int **pairing, int N, char *fname){
+  
+  FILE *f;
+  int i, j, num;
+  char buff[256];
+  char *ptr;
+
+  f = fopen(fname, "r");
+  if (!f){
+    printf("Error opening file \"%s\"!!!! Exiting....\n", fname);
+    exit(2);
+  }
+
+  if (*pairing == NULL){
+    *pairing = malloc(N * sizeof(int));
+    init_pairing_natural(*pairing, N);
+  }
+  
+  num = 0;
+  while(num < N){
+    fgets(buff, 255, f);
+    if (buff[0] == '#')
+      continue;
+    ptr = strtok(buff, " "); /* read the first node */
+    i = atoi(ptr);
+    ptr = strtok(NULL, " "); /* read the second node */
+    j = atoi(ptr);
+    (*pairing)[i] = j;
+    num += 1;
+  }
+}
+
+
+void dump_pairing(int *pairing, int N){
+  int i;
+
+  for(i=0; i< N; i ++){
+    printf("%d %d\n", i, pairing[i]);
+  }
+}
+
+void copy_pairing(int *p1, int *p2, int N){
+  int i;
+  
+  for (i=0 ; i < N; i ++){
+    p2[i] = p1[i];
+  }
+}