Fixed typos and added the tracker file format.

diff --git a/README.txt b/README.txt
index 793710b..eb8a26f 100644 (file)
--- a/README.txt
+++ b/README.txt
@@ -39,10 +39,9 @@ family of paths in this graph that minimizes the sum of edge lengths.
 
 This means that it will iteratively add paths as long as it can find
 some with negative length. If there are no such path, it will compute
-no path at all. Note that the solution it finds is globally
-optimal. Note that the procedure is similar to that of KSP, in the
-sense that the family it computes eventually is globally optimal, even
-if the procedure is iterative.
+no path at all. Note that the procedure is similar to that of KSP, in
+the sense that the family it computes eventually is globally optimal,
+even if the computation is iterative.
 
 The Tracker class allows
 
@@ -57,8 +56,8 @@ The Tracker class allows
  (2) to define a number of time steps
 
  (3) to set for every location and time a detection score, which
- should be equal to log(P(Y = 1 | X)/P(Y = 0 | X)) where Y stands for
- the location occupancy and X for the observations.
+     should be equal to log(P(Y = 1 | X)/P(Y = 0 | X)) where Y stands
+     for the location occupancy and X for the observations.
 
 From this setting, it computes the best set of disjoint trajectories
 consistent with the topology, which maximizes the overall detection
@@ -69,14 +68,35 @@ The Tracker class uses the MTPGraph. From the definition of the
 spatial topology, it builds a graph with one source, one sink, and two
 nodes per location and time. This structure ensures the trajectories
 computed by the tracker to be node-disjoint by forcing the paths
-computed by the MTPGraph to be edge-disjoint. The edges from the
-source or to the sink, or between these pairs, are of length zero, and
-the edge between the two nodes of such a pair has a length equal to
-the opposite of the detection score.
+computed by the MTPGraph to be edge-disjoint.
+
+The edges from the source or to the sink, or between these pairs, are
+of length zero, and the edge between the two nodes of such a pair has
+a length equal to the opposite of the detection score.
 
 The file mtp.cc gives a very simple usage example of the Tracker
 class.
 
+The tracker data file one can read with Tracker::read has the
+following format (with L the number of locations and T the number of
+time steps):
+
+---------------------------- snip snip -------------------------------
+L T
+
+allowed_motion_from_1_to_1 ... allowed_motion_from_1_to_L
+...
+allowed_motion_from_L_to_1 ... allowed_motion_from_L_to_L
+
+is_an_entrance_1 ... is_an_entrance_L
+
+is_an_exit_1 ... is_an_exit_L
+
+detection_score_1_1 ... detection_score_1_L
+...
+detection_score_T_1 ... detection_score_T_L
+---------------------------- snip snip -------------------------------
+
 --
 François Fleuret
 August 2012