1.1 --- a/doc/groups.dox	Tue Oct 09 09:36:54 2007 +0000
     1.2 +++ b/doc/groups.dox	Tue Oct 09 15:46:12 2007 +0000
     1.3 @@ -97,6 +97,57 @@
     1.4  make arithmetic operations between one or two maps (negation, scaling,
     1.5  addition, multiplication etc.) or e.g. convert a map to another one
     1.6  of different Value type.
     1.7 +
     1.8 +The typical usage of this classes is the passing implicit maps to
     1.9 +algorithms.  If a function type algorithm is called then the function
    1.10 +type map adaptors can be used comfortable. For example let's see the
    1.11 +usage of map adaptors with the \c graphToEps() function:
    1.12 +\code
    1.13 +  Color nodeColor(int deg) {
    1.14 +    if (deg >= 2) {
    1.15 +      return Color(0.5, 0.0, 0.5);
    1.16 +    } else if (deg == 1) {
    1.17 +      return Color(1.0, 0.5, 1.0);
    1.18 +    } else {
    1.19 +      return Color(0.0, 0.0, 0.0);
    1.20 +    }
    1.21 +  }
    1.22 +  
    1.23 +  Graph::NodeMap<int> degree_map(graph);
    1.24 +  
    1.25 +  graphToEps(graph, "graph.eps")
    1.26 +    .coords(coords).scaleToA4().undirected()
    1.27 +    .nodeColors(composeMap(functorMap(nodeColor), degree_map)) 
    1.28 +    .run();
    1.29 +\endcode 
    1.30 +The \c functorMap() function makes an \c int to \c Color map from the
    1.31 +\e nodeColor() function. The \c composeMap() compose the \e degree_map
    1.32 +and the previous created map. The composed map is proper function to
    1.33 +get color of each node.
    1.34 +
    1.35 +The usage with class type algorithms is little bit harder. In this
    1.36 +case the function type map adaptors can not be used, because the
    1.37 +function map adaptors give back temporarly objects.
    1.38 +\code
    1.39 +  Graph graph;
    1.40 +  
    1.41 +  typedef Graph::EdgeMap<double> DoubleEdgeMap;
    1.42 +  DoubleEdgeMap length(graph);
    1.43 +  DoubleEdgeMap speed(graph);
    1.44 +  
    1.45 +  typedef DivMap<DoubleEdgeMap, DoubleEdgeMap> TimeMap;
    1.46 +  
    1.47 +  TimeMap time(length, speed);
    1.48 +  
    1.49 +  Dijkstra<Graph, TimeMap> dijkstra(graph, time);
    1.50 +  dijkstra.run(source, target);
    1.51 +\endcode
    1.52 +
    1.53 +We have a length map and a maximum speed map on a graph. The minimum
    1.54 +time to pass the edge can be calculated as the division of the two
    1.55 +maps which can be done implicitly with the \c DivMap template
    1.56 +class. We use the implicit minimum time map as the length map of the
    1.57 +\c Dijkstra algorithm.
    1.58  */
    1.59  
    1.60  /**
    1.61 @@ -115,9 +166,10 @@
    1.62  LEMON provides flexible data structures
    1.63  to work with paths.
    1.64  
    1.65 -All of them have the same interface, especially they can be built or extended
    1.66 -using a standard Builder subclass. This make is easy to have e.g. the Dijkstra
    1.67 -algorithm to store its result in any kind of path structure.
    1.68 +All of them have similar interfaces, and it can be copied easily with
    1.69 +assignment operator and copy constructor. This make it easy and
    1.70 +efficient to have e.g. the Dijkstra algorithm to store its result in
    1.71 +any kind of path structure.
    1.72  
    1.73  \sa lemon::concepts::Path
    1.74