alpar@209: /* -*- mode: C++; indent-tabs-mode: nil; -*- alpar@156: * alpar@209: * This file is a part of LEMON, a generic C++ optimization library. alpar@156: * alpar@156: * Copyright (C) 2003-2008 alpar@156: * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport alpar@156: * (Egervary Research Group on Combinatorial Optimization, EGRES). alpar@156: * alpar@156: * Permission to use, modify and distribute this software is granted alpar@156: * provided that this copyright notice appears in all copies. For alpar@156: * precise terms see the accompanying LICENSE file. alpar@156: * alpar@156: * This software is provided "AS IS" with no warranty of any kind, alpar@156: * express or implied, and with no claim as to its suitability for any alpar@156: * purpose. alpar@156: * alpar@156: */ alpar@156: alpar@156: namespace lemon { alpar@156: /*! alpar@156: alpar@156: alpar@156: ladanyi@236: \page lgf-format LEMON Graph Format (LGF) alpar@156: alpar@156: The \e LGF is a column oriented alpar@156: file format for storing graphs and associated data like alpar@156: node and edge maps. alpar@156: alpar@156: Each line with \c '#' first non-whitespace alpar@156: character is considered as a comment line. alpar@156: alpar@156: Otherwise the file consists of sections starting with alpar@156: a header line. The header lines starts with an \c '@' character followed by the alpar@156: type of section. The standard section types are \c \@nodes, \c alpar@156: \@arcs and \c \@edges alpar@156: and \@attributes. Each header line may also have an optional alpar@156: \e name, which can be use to distinguish the sections of the same alpar@156: type. alpar@156: alpar@156: The standard sections are column oriented, each line consists of alpar@156: tokens separated by whitespaces. A token can be \e plain or alpar@156: \e quoted. A plain token is just a sequence of non-whitespace characters, alpar@156: while a quoted token is a alpar@156: character sequence surrounded by double quotes, and it can also alpar@209: contain whitespaces and escape sequences. alpar@156: alpar@156: The \c \@nodes section describes a set of nodes and associated kpeter@192: maps. The first is a header line, its columns are the names of the alpar@156: maps appearing in the following lines. alpar@156: One of the maps must be called \c alpar@156: "label", which plays special role in the file. alpar@156: The following alpar@156: non-empty lines until the next section describes nodes of the alpar@156: graph. Each line contains the values of the node maps alpar@156: associated to the current node. alpar@156: alpar@156: \code alpar@156: @nodes kpeter@212: label coordinates size title kpeter@212: 1 (10,20) 10 "First node" kpeter@212: 2 (80,80) 8 "Second node" kpeter@212: 3 (40,10) 10 "Third node" alpar@156: \endcode alpar@156: alpar@922: The \c \@arcs section is very similar to the \c \@nodes section, it alpar@922: again starts with a header line describing the names of the maps, but alpar@922: the \c "label" map is not obligatory here. The following lines alpar@922: describe the arcs. The first two tokens of each line are the source alpar@922: and the target node of the arc, respectively, then come the map alpar@156: values. The source and target tokens must be node labels. alpar@156: alpar@156: \code alpar@156: @arcs kpeter@212: capacity alpar@156: 1 2 16 alpar@156: 1 3 12 alpar@156: 2 3 18 alpar@156: \endcode alpar@156: alpar@922: If there is no map in the \c \@arcs section at all, then it must be alpar@922: indicated by a sole '-' sign in the first line. alpar@922: alpar@922: \code alpar@922: @arcs alpar@922: - alpar@922: 1 2 alpar@922: 1 3 alpar@922: 2 3 alpar@922: \endcode alpar@922: kpeter@313: The \c \@edges is just a synonym of \c \@arcs. The \@arcs section can deba@201: also store the edge set of an undirected graph. In such case there is deba@201: a conventional method for store arc maps in the file, if two columns alpar@922: have the same caption with \c '+' and \c '-' prefix, then these columns deba@201: can be regarded as the values of an arc map. alpar@156: alpar@156: The \c \@attributes section contains key-value pairs, each line deba@201: consists of two tokens, an attribute name, and then an attribute deba@201: value. The value of the attribute could be also a label value of a deba@201: node or an edge, or even an edge label prefixed with \c '+' or \c '-', deba@201: which regards to the forward or backward directed arc of the deba@201: corresponding edge. alpar@156: alpar@156: \code alpar@156: @attributes alpar@156: source 1 alpar@156: target 3 alpar@156: caption "LEMON test digraph" alpar@156: \endcode alpar@156: deba@162: The \e LGF can contain extra sections, but there is no restriction on deba@162: the format of such sections. deba@162: alpar@156: */ alpar@156: } alpar@156: alpar@156: // LocalWords: whitespace whitespaces