Graph's visualization in Linux

A few days ago my friend show me a very simple and convenient program to visualize graphs - "graphviz". It's free and can be used in Linux, Solaris, Windows and Mac. For drawing graphs "graphviz" uses DOT language.

Let's create a simple graph. Open text editor and paste this code:

digraph SimpleGraph {

    rankdir=LR;

    node [shape=circle];

    ranksep=0.5;

    node [style=dashed];
    0 -> 1 [label="A"];
    node [style=solid];

    0 -> 2 [label="B"];

    1 -> 3 [label="C"];

    2 -> 1 [label="D", style=dotted];

    2 -> 3 [label="E", style=dotted];

    2 -> 4 [label="F"];

    3 -> 5 [label="G"];

    4 -> 5 [label="H"];

}

• digraph - this graph keyword allows to build a directed graph;
• rankdir=LR - allows to set graph orietation (from left to right), by default graph orientation is from top to bottom;
• [shape=circle] - setting node form;
• ranksep=0.5 - distance between nodes;
• node [style=dashed] - setting line form for node.

Save file with .gv extension. Open terminal and enter this command which allows to import our graph to .png format:

$ dot -T png simple_graph.gv > simple_graph.png

or

$ dot -T png simple_graph.gv -o simple_graph.png

Let's see our graph in graphical representation:

Istead .png you may use one of these formats:

bmp canon cmap cmapx cmapx_np dot eps fig gd gd2 gif gtk gv ico imap imap_np ismap jpe jpeg jpg pdf plain plain-ext png ps ps2 svg svgz tga tif tiff tk vml vmlz vrml wbmp x11 xdot xlib

Here you can download "graphviz" for your system - http://www.graphviz.org/Download..php

Here you can find a good HOWTOs - http://www.graphviz.org/Documentation.php

Node, Edge and Graph Attributes - http://www.graphviz.org/doc/info/attrs.html

Node Shapes - http://www.graphviz.org/doc/info/shapes.html