EVOLUTION-MANAGER
Edit File: graph_from_graphdb.html
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><title>R: Load a graph from the graph database for testing graph...</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <link rel="stylesheet" type="text/css" href="R.css" /> </head><body> <table width="100%" summary="page for graph_from_graphdb {igraph}"><tr><td>graph_from_graphdb {igraph}</td><td style="text-align: right;">R Documentation</td></tr></table> <h2>Load a graph from the graph database for testing graph isomorphism.</h2> <h3>Description</h3> <p>This function downloads a graph from a database created for the evaluation of graph isomorphism testing algothitms. </p> <h3>Usage</h3> <pre> graph_from_graphdb( url = NULL, prefix = "iso", type = "r001", nodes = NULL, pair = "A", which = 0, base = "http://cneurocvs.rmki.kfki.hu/graphdb/gzip", compressed = TRUE, directed = TRUE ) </pre> <h3>Arguments</h3> <table summary="R argblock"> <tr valign="top"><td><code>url</code></td> <td> <p>If not <code>NULL</code> it is a complete URL with the file to import.</p> </td></tr> <tr valign="top"><td><code>prefix</code></td> <td> <p>Gives the prefix. See details below. Possible values: <code>iso</code>, <code>i2</code>, <code>si4</code>, <code>si6</code>, <code>mcs10</code>, <code>mcs30</code>, <code>mcs50</code>, <code>mcs70</code>, <code>mcs90</code>.</p> </td></tr> <tr valign="top"><td><code>type</code></td> <td> <p>Gives the graph type identifier. See details below. Possible values: <code>r001</code>, <code>r005</code>, <code>r01</code>, <code>r02</code>, <code>m2D</code>, <code>m2Dr2</code>, <code>m2Dr4</code>, <code>m2Dr6</code> <code>m3D</code>, <code>m3Dr2</code>, <code>m3Dr4</code>, <code>m3Dr6</code>, <code>m4D</code>, <code>m4Dr2</code>, <code>m4Dr4</code>, <code>m4Dr6</code>, <code>b03</code>, <code>b03m</code>, <code>b06</code>, <code>b06m</code>, <code>b09</code>, <code>b09m</code>.</p> </td></tr> <tr valign="top"><td><code>nodes</code></td> <td> <p>The number of vertices in the graph.</p> </td></tr> <tr valign="top"><td><code>pair</code></td> <td> <p>Specifies which graph of the pair to read. Possible values: <code>A</code> and <code>B</code>.</p> </td></tr> <tr valign="top"><td><code>which</code></td> <td> <p>Gives the number of the graph to read. For every graph type there are a number of actual graphs in the database. This argument specifies which one to read.</p> </td></tr> <tr valign="top"><td><code>base</code></td> <td> <p>The base address of the database. See details below.</p> </td></tr> <tr valign="top"><td><code>compressed</code></td> <td> <p>Logical constant, if TRUE than the file is expected to be compressed by gzip. If <code>url</code> is <code>NULL</code> then a ‘<code>.gz</code>’ suffix is added to the filename.</p> </td></tr> <tr valign="top"><td><code>directed</code></td> <td> <p>Logical constant, whether to create a directed graph.</p> </td></tr> </table> <h3>Details</h3> <p><code>graph_from_graphdb</code> reads a graph from the graph database from an FTP or HTTP server or from a local copy. It has two modes of operation: </p> <p>If the <code>url</code> argument is specified then it should the complete path to a local or remote graph database file. In this case we simply call <code><a href="read_graph.html">read_graph</a></code> with the proper arguments to read the file. </p> <p>If <code>url</code> is <code>NULL</code>, and this is the default, then the filename is assembled from the <code>base</code>, <code>prefix</code>, <code>type</code>, <code>nodes</code>, <code>pair</code> and <code>which</code> arguments. </p> <p>Unfortunately the original graph database homepage is now defunct, but see its old version at <a href="http://web.archive.org/web/20090215182331/http://amalfi.dis.unina.it/graph/db/doc/graphdbat.html">http://web.archive.org/web/20090215182331/http://amalfi.dis.unina.it/graph/db/doc/graphdbat.html</a> for the actual format of a graph database file and other information. </p> <h3>Value</h3> <p>A new graph object. </p> <h3>Examples</h3> <pre> g <- graph_from_graphdb(prefix="iso", type="r001", nodes=20, pair="A", which=10, compressed=TRUE) g2 <- graph_from_graphdb(prefix="iso", type="r001", nodes=20, pair="B", which=10, compressed=TRUE) graph.isomorphic.vf2(g, g2) % should be TRUE g3 <- graph_from_graphdb(url=paste(sep="/", "http://cneurocvs.rmki.kfki.hu", "graphdb/gzip/iso/bvg/b06m", "iso_b06m_m200.A09.gz")) </pre> <h3>Author(s)</h3> <p>Gabor Csardi <a href="mailto:csardi.gabor@gmail.com">csardi.gabor@gmail.com</a> </p> <h3>References</h3> <p>M. De Santo, P. Foggia, C. Sansone, M. Vento: A large database of graphs and its use for benchmarking graph isomorphism algorithms, <em>Pattern Recognition Letters</em>, Volume 24, Issue 8 (May 2003) </p> <h3>See Also</h3> <p><code><a href="read_graph.html">read_graph</a></code>, <code><a href="isomorphic.html">graph.isomorphic.vf2</a></code> </p> <hr /><div style="text-align: center;">[Package <em>igraph</em> version 1.3.5 <a href="00Index.html">Index</a>]</div> </body></html>