Comment update.

[mtp.git] / mtp_example.cc

diff --git a/mtp_example.cc b/mtp_example.cc
index 84ef153..c1f6778 100644 (file)
--- a/mtp_example.cc
+++ b/mtp_example.cc
@@ -24,6 +24,7 @@
 
 #include <iostream>
 #include <fstream>
+#include <stdlib.h>
 
 using namespace std;
 
@@ -49,20 +50,31 @@ int main(int argc, char **argv) {
 
   tracker->allocate(nb_time_steps, nb_locations);
 
-  // We define the spatial structures by stating what are the possible
-  // motions of targets, and what are the entrances and the
-  // exits.
+  // We define the spatial structure by stating what are the possible
+  // motions of targets, and what are the entrances and the exits.
 
   // Here our example is a 1D space with motions from any location to
   // any location less than motion_amplitude away, entrance at
-  // location 0 and exit at location nb_locations-1.
+  // location 0 (or in the first time frame, i.e. targets can already
+  // be in the scene when the sequence starts) and exit at location
+  // nb_locations-1 (or from the last time frame, i.e. targets can
+  // still be present when the sequence finishes)
 
   for(int l = 0; l < nb_locations; l++) {
-    for(int k = 0; k < nb_locations; k++) {
-      tracker->allowed_motion[l][k] = abs(l - k) <= motion_amplitude;
+    for(int m = 0; m < nb_locations; m++) {
+      tracker->allowed_motions[l][m] = abs(l - m) <= motion_amplitude;
+    }
+  }
+
+  for(int t = 0; t < nb_time_steps; t++) {
+    for(int l = 0; l < nb_locations; l++) {
+      // We allow targets to enter in the first time frame, or in
+      // location 0
+      tracker->entrances[t][l] = (t == 0 || l == 0);
+      // We allow targets to leave from the last time frame, or from
+      // location nb_locations-1
+      tracker->exits[t][l] = (t == nb_time_steps - 1 || l == nb_locations-1);
     }
-    tracker->entrances[0] = 1;
-    tracker->exits[nb_locations - 1] = 1;
   }
 
   // We construct the graph corresponding to this structure
@@ -84,14 +96,14 @@ int main(int argc, char **argv) {
     }
   }
 
-  // Then we two targets with the typical local minimum:
+  // Then we add two targets with a typical tracking local minimum
   //
   // * Target A moves from location 0 to the middle, stays there for a
-  //   while, and comes back, and is strongly detected on the first
+  //   while, and comes back. It is strongly detected on the first
   //   half
   //
   // * Target B moves from location nb_locations-1 to the middle, stay
-  //   there for a while, and comes back, and is strongly detected on
+  //   there for a while, and comes back. It is strongly detected on
   //   the second half
 
   int la, lb; // Target locations
@@ -116,12 +128,13 @@ int main(int argc, char **argv) {
     tracker->detection_scores[t][lb] = sb;
   }
 
-  { // Write down the tracker setting
+  { // Write down the tracker setting, so that we can use it as an
+    // example for the mtp command line
     ofstream out_tracker("tracker.dat");
     tracker->write(&out_tracker);
   }
 
-  // Does the tracking per se
+  // Performs the tracking per se
 
   tracker->track();
 
@@ -133,7 +146,7 @@ int main(int argc, char **argv) {
          << " starting at " << tracker->trajectory_entrance_time(t)
          << ", duration " << tracker->trajectory_duration(t)
          << ", score " << tracker->trajectory_score(t)
-         << ", through nodes ";
+         << ", through locations";
     for(int u = 0; u < tracker->trajectory_duration(t); u++) {
       cout << " " << tracker->trajectory_location(t, u);
     }