2 \page getstart How to start using LEMON
4 In this page we detail how to start using LEMON, from downloading it to
5 your computer, through the steps of installation, to showing a simple
6 "Hello World" type program that already uses LEMON. We assume that you
7 have a basic knowledge of your operating system and \c C++ programming
8 language. The procedure is pretty straightforward, but if you have any
9 difficulties don't hesitate to
10 <a href="http://lemon.cs.elte.hu/mailinglists.html">ask</a>.
12 \section requirementsLEMON Hardware and software requirements
14 In LEMON we use C++ templates heavily, thus compilation takes a
15 considerable amount of time and memory. So some decent box would be
16 advantageous. But otherwise there are no special hardware requirements.
18 You will need a recent C++ compiler. Our primary target is the GNU C++
19 Compiler (g++), from version 3.3 upwards. We also checked the Intel C
20 compiler (icc). Microsoft Visual C++ .NET version was also reported to
21 work (but not the earlier versions). If you want to develop with LEMON
22 under Windows you could consider using Cygwin.
25 In this description we will suppose a linux environment and GNU C Compiler.
27 \section downloadLEMON How to download LEMON
29 You can download LEMON from the LEMON web site:
30 http://lemon.cs.elte.hu/dowload.html.
31 There you will find released versions in form of <tt>.tar.gz</tt> files.
32 If you want a developer version (for example you want to contribute in
33 developing the library LEMON) then you might want to use our Subversion
34 repository. This case is not detailed here, so from now on we suppose that
35 you downloaded a tar.gz file.
39 \section installLEMON How to install LEMON
41 In order to install LEMON you have to do the following
43 Download the tarball (named <tt>lemon-x.y.z.tar.gz</tt> where \c x,\c y
44 and \c z are numbers indicating the version of the library: in our example
45 we will have <tt>lemon-0.3.1.tar.gz</tt>) and issue the following
49 tar xvzf lemon-0.3.1.tar.gz
53 make check #(This is optional, but recomended. It runs a bunch of tests.)
57 These commands install LEMON under \c /usr/local (you will
58 need root privileges to be able to install to that
59 directory). If you want to install it to some other place, then
60 pass the \c --prefix=DIR flag to \c ./configure. In what follows
61 we will assume that you were able to install to directory
62 \c /usr/local, otherwise some extra care is to be taken to use the
65 We briefly explain these commands below.
68 tar xvzf lemon-0.3.1.tar.gz
70 This command untars the <tt>tar.gz</tt> file into a directory named <tt>
81 Does some configuration (creates makefiles etc).
82 \todo Explain the most important switches here (gui, doc, glpk, cplex).
87 This command compiles the non-template part of LEMON into
88 <b>libemon.a</b> file. It also compiles some benchmark and demo
94 This is an optional step: it runs the test programs that we
95 developed for LEMON to check whether the library works properly on
101 This will copy the directory structure to its final destination (e.g. to \c
102 /usr/local) so that your system can access it. This command should
103 be issued as "root", unless you provided a \c --prefix switch to
104 the \c cofugure to install the library in non-default location.
106 \section helloworld My first program using LEMON
108 If you have installed LEMON on your system you can paste the
109 following code segment into a file (named e.g. \c hello_lemon.cc)
110 to have a first working program that uses library LEMON.
114 #include <lemon/list_graph.h>
118 typedef lemon::ListGraph Graph;
119 typedef Graph::EdgeIt EdgeIt;
120 typedef Graph::NodeIt NodeIt;
121 using lemon::INVALID;
125 for (int i = 0; i < 3; i++)
128 for (NodeIt i(g); i!=INVALID; ++i)
129 for (NodeIt j(g); j!=INVALID; ++j)
130 if (i != j) g.addEdge(i, j);
132 std::cout << "Nodes:";
133 for (NodeIt i(g); i!=INVALID; ++i)
134 std::cout << " " << g.id(i);
135 std::cout << std::endl;
137 std::cout << "Edges:";
138 for (EdgeIt i(g); i!=INVALID; ++i)
139 std::cout << " (" << g.id(g.source(i)) << "," << g.id(g.target(i)) << ")";
140 std::cout << std::endl;
144 First let us briefly explain how this program works.
146 ListGraph is one of LEMON's graph classes. It is based on linked lists,
147 therefore iterating throuh its edges and nodes is fast.
149 After some convenient typedefs we create a graph and add three nodes to it.
150 Then we add edges to it to form a complete graph.
152 Then we iterate through all nodes of the graph. We use a constructor of the
153 node iterator to initialize it to the first node. The operator++ is used to
154 step to the next node. Using operator++ on the iterator pointing to the last
155 node invalidates the iterator i.e. sets its value to
156 \ref lemon::INVALID "INVALID". This is what we exploit in the stop condition.
158 We can also iterate through all edges of the graph very similarly. The
160 \c source member functions can be used to access the endpoints of an edge.
162 If you have saved the preceding code into a file named, say, \c
163 hello_lemon.cc and your installation of LEMON into directory \c
164 /usr/local was successful then it is very easy to compile this
165 program with the following command (the argument <tt>-lemon</tt>
166 tells the compiler that we are using the installed library LEMON):
169 g++ hello_lemon.cc -o hello_lemon -lemon
172 As a result you will get the exacutable \c hello_lemon in
173 this directory that you can run by the command
179 If everything has gone well then the previous code fragment prints
185 Edges: (0,2) (1,2) (0,1) (2,1) (1,0) (2,0)
190 If you want to see more features, go to the
191 \ref quicktour "Quick Tour to LEMON",
192 if you want to see see some demo programs then go to our
193 \ref demoprograms "Demo Programs" page!