levenshtein.c in phonetics-1.5.4

- old
+ new

@@ -53,13 +53,13 @@
 
   for (i = 0; i < string1_length; i++) {
     string1[i] = NUM2INT(string1_ruby[i]);
     debug("string1[%d] = %d\n", i, string1[i]);
   }
-  for (i = 0; i < string2_length; i++) {
-    string2[i] = NUM2INT(string2_ruby[i]);
-    debug("string2[%d] = %d\n", i, string2[i]);
+  for (j = 0; j < string2_length; j++) {
+    string2[j] = NUM2INT(string2_ruby[j]);
+    debug("string2[%d] = %d\n", i, string2[j]);
   }
 
   // one-dimensional representation of 2 dimentional array len(string1)+1 *
   // len(string2)+1
   d = malloc((sizeof(double)) * (string1_length+1) * (string2_length+1));
@@ -79,12 +79,12 @@
 
   // Then walk through the matrix and fill in each cell with the lowest-cost
   // phonetic edit distance for that matrix cell.
   // (Skipping i=0 and j=0 because set_initial filled in all cells where i
   // or j are zero-valued)
-  for(j = 1; j <= string2_length; j++){
-    for(i = 1; i <= string1_length; i++){
+  for (j = 1; j <= string2_length; j++){
+    for (i = 1; i <= string1_length; i++){
 
       // The cost of deletion or addition is the Levenshtein distance
       // calculation (the value in the cell to the left, upper-left, or above)
       // plus the phonetic distance between the sound we're moving from to the
       // new one.
@@ -139,28 +139,26 @@
 // Subsequent values are the cumulative phonetic distance between each
 // phoneme within the same string.
 // "aek" -> [0.0, 1.0, 1.61, 2.61]
 void set_initial(double *d, int *string1, int string1_length, int *string2, int string2_length, bool verbose) {
 
-  double distance_between_first_phonemes;
+  double initial_distance;
   int i, j;
 
   if (string1_length == 0 || string2_length == 0) {
-    distance_between_first_phonemes = 0.0;
-  } else if (string1[0] == string2[0]) {
-    distance_between_first_phonemes = 0.0;
+    initial_distance = 0.0;
   } else {
-    distance_between_first_phonemes = phonetic_cost(string1[0], string2[0]);
+    initial_distance = 1.0;
   }
 
+  // The top-left is 0, the cell to the right and down are each 1 to start
   d[0] = (double) 0.0;
-  // Set the first value of string1's sequential phonetic calculation (maps to
-  // cell x=1, y=0)
-  d[1] = distance_between_first_phonemes;
-  // And of string2 (maps to cell x=0, y=1)
+  if (string1_length > 0) {
+    d[1] = initial_distance;
+  }
   if (string2_length > 0) {
-    d[string1_length+1] = distance_between_first_phonemes;
+    d[string1_length+1] = initial_distance;
   }
 
   debug("string1 length: %d\n", string1_length);
   for (i=2; i <= string1_length; i++) {
     // The cost of adding the next phoneme is the cost so far plus the phonetic
@@ -169,9 +167,17 @@
   }
   debug("string2 length: %d\n", string2_length);
   for (j=2; j <= string2_length; j++) {
     // The same exact pattern down the left side of the matrix
     d[j * (string1_length+1)] = d[(j - 1) * (string1_length+1)] + phonetic_cost(string2[j-2], string2[j-1]);
+  }
+
+  // And zero out the rest. If you're reading this please edit this to be
+  // faster.
+  for (j=1; j <= string2_length; j++) {
+    for (i=1; i <= string1_length; i++) {
+      d[j * (string1_length+1) + i] = (double) 0.0;
+    }
   }
 }
 
 // A handy visualization for developers
 void print_matrix(double *d, int *string1, int string1_length, int *string2, int string2_length, bool verbose) {