doc/quicktour.dox
author alpar
Thu, 24 Feb 2005 17:48:25 +0000
changeset 1177 e41c2907fb49
parent 1170 fb0159aa582d
child 1181 848b6006941d
permissions -rw-r--r--
Fix 'make distcheck' failure.
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/**
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\page quicktour Quick Tour to LEMON
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Let us first answer the question <b>"What do I want to use LEMON for?"
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</b>. 
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LEMON is a C++ library, so you can use it if you want to write C++ 
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programs. What kind of tasks does the library LEMON help to solve? 
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It helps to write programs that solve optimization problems that arise
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frequently when <b>designing and testing certain networks</b>, for example
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in telecommunication, computer networks, and other areas that I cannot
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think of now. A very natural way of modelling these networks is by means
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of a <b> graph</b> (we will always mean a directed graph by that). 
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So if you want to write a program that works with 
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graphs then you might find it useful to use our library LEMON.
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Some examples are the following:
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- First we give two examples that show how to instantiate a graph. The
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first one shows the methods that add nodes and edges, but one will
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usually use the second way which reads a graph from a stream (file).
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-# The following code fragment shows how to fill a graph with data.
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 \code
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  typedef ListGraph Graph;
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  typedef Graph::Edge Edge;
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  typedef Graph::InEdgeIt InEdgeIt;
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  typedef Graph::OutEdgeIt OutEdgeIt;
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  typedef Graph::EdgeIt EdgeIt;
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  typedef Graph::Node Node;
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  typedef Graph::NodeIt NodeIt;
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  Graph g;
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  for (int i = 0; i < 3; i++)
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    g.addNode();
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  for (NodeIt i(g); i!=INVALID; ++i)
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    for (NodeIt j(g); j!=INVALID; ++j)
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      if (i != j) g.addEdge(i, j);
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 \endcode 
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 -#
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- If you want to solve some transportation problems in a network then 
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you will want to find shortest paths between nodes of a graph. This is 
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usually solved using Dijkstra's algorithm. A utility
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that solves this is  the \ref lemon::Dijkstra "LEMON Dijkstra class".
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A simple program using the \ref lemon::Dijkstra "LEMON Dijkstra class" is
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as follows (we assume that the graph is already given in the memory):
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\code
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\endcode
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- If you want to design a network and want to minimize the total length
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of wires then you might be looking for a <b>minimum spanning tree</b> in
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an undirected graph. This can be found using the Kruskal algorithm: the 
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class \ref lemon::Kruskal "LEMON Kruskal class" does this job for you.
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The following code fragment shows an example:
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\code
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\endcode
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Some more detailed introduction can be obtained by following the links 
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below:
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\ref graphs "Graph structures"
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play a central role in LEMON, so if you are new to the library,
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you probably should start \ref graphs "here".
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(You can also find that page along with others under
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<a class="el" href="pages.html"> Related Pages </a>.)
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If you are 
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interested in data structures and algorithms in more details, then
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you should browse the reference manual part of the documentation.
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Section <a class="el" href="modules.html"> Modules </a>
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 is a good starting point for this.
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*/