Changed the date.

[mtp.git] / README.txt

diff --git a/README.txt b/README.txt
index 026f508..807f567 100644 (file)
--- a/README.txt
+++ b/README.txt
@@ -1,6 +1,6 @@
 
-                     Multi-Tracked Paths (MTP)
-                     -------------------------
+                       Multi-Tracked Paths (MTP)
+                       -------------------------
 
 * INTRODUCTION
 
@@ -14,7 +14,25 @@ in
   2011.
 
 This implementation is not the reference implementation used for the
-experiments presented in this article.
+experiments presented in this article. It does not require any
+library, and uses a Dijkstra with a Binary Heap for the min-queue,
+instead of a Fibonacci heap.
+
+This software package includes three commands:
+
+ - mtp is the generic command to use in practice. It takes tracking
+   parameters as input, and prints the tracked trajectories as
+   output. The format for these parameters is given at the bottom of
+   this documentation.
+
+ - mtp_example creates a tracking toy example, and runs the tracking
+   algorithm on it. It gives an example of how to use MTPTracker on a
+   configuration produced dynamically, and produces a test input file
+   for the mtp command.
+
+ - mtp_stress_test creates a larger problem with a lot of noise and
+   multiple trajectories, to check the behavior of the code under
+   slightly more complex situations.
 
 * INSTALLATION
 
@@ -29,7 +47,7 @@ tracker.dat, and print the optimal detected trajectories.
 
 If you now execute
 
-  ./mtp tracker.dat
+  ./mtp --verbose --trajectory-file result.trj --graph-file graph.dot tracker.dat
 
 It will load the file tracker.dat saved by the previous command, run
 the detection, save the detected trajectories in result.trj, and the
@@ -55,11 +73,11 @@ 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 MTPTracker is defined by
+The MTPTracker takes as input
 
- (1) a spatial topology composed of
+ (1) a number of locations and a number of time steps
 
-     - a number of locations
+ (2) a spatial topology composed of
 
      - the allowed motions between them (a Boolean flag for each pair
        of locations from/to)
@@ -68,31 +86,31 @@ The MTPTracker is defined by
 
      - the exits (a Boolean flag for each location and time step)
 
- (2) a number of time steps
-
  (3) a detection score for every location and time, which stands for
 
              log( P(Y(l,t) = 1 | X) / P(Y(l,t) = 0 | X) )
 
      where Y is the occupancy of location l at time t and X is the
-     available observation.
+     available observation. Hence, this score is negative on locations
+     where the probability that the location is occupied is close to
+     0, and positive when it is close to 1.
 
-From this setting, MTPTracker has methods to compute the best set of
+From this parameters, the MTPTracker can compute the best set of
 disjoint trajectories consistent with the defined topology, which
 maximizes the overall detection score (i.e. the sum of the detection
-scores of the nodes visited by the trajectories). If no trajectory of
-total positive detection score exists, this optimal set of
-trajectories will be empty.
-
-The MTPTracker is a wrapper around the MTPGraph class. From the
-defined spatial topology and number of time steps, it builds a graph
-with one source, one sink, and two nodes per location and time. The
-edges from the source or to the sink, or between these pairs of nodes,
-are of length zero, and the edges between the two nodes of such a pair
-have negative lengths, equal to the opposite of the corresponding
-detection scores. This structure also ensures that the trajectories
-computed by the MTPTracker will be node-disjoint, since the
-trajectories computed by the MTPGraph are edge-disjoint.
+scores of the nodes visited by the trajectories). In particular, if no
+trajectory of total positive detection score exists, this optimal set
+of trajectories is empty.
+
+An MTPTracker is a wrapper around an MTPGraph. From the defined
+spatial topology and number of time steps, it builds a graph with one
+source, one sink, and two nodes per location and time. The edges from
+the source or to the sink, or between these pairs of nodes, are of
+length zero, and the edges between the two nodes of such a pair have
+negative lengths, equal to the opposite of the corresponding detection
+scores. This structure ensures that the trajectories computed by the
+MTPTracker will be node-disjoint, since the trajectories computed by
+the MTPGraph are edge-disjoint.
 
 The file mtp_example.cc gives a very simple usage example of the
 MTPTracker class by setting the tracker parameters dynamically, and
@@ -131,4 +149,4 @@ structure
 
 --
 François Fleuret
-October 2012
+January 2013