igraph (version 0.5.4-1)

graph.graphdb: Load a graph from the graph database for testing graph isomorphism.

Description

This function downloads a graph from a database created for the evaluation of graph isomorphism testing algothitms.

Usage

graph.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)

Arguments

url
If not NULL it is a complete URL with the file to import.
prefix
Gives the prefix. See details below. Possible values: iso, i2, si4, si6, mcs10, mcs30, mcs50, mcs70, mcs90.
type
Gives the graph type identifier. See details below. Possible values: r001, r005, r01, r02, m2D, m2Dr2, m2Dr4, m2Dr6 m3D,
nodes
The number of vertices in the graph.
pair
Specifies which graph of the pair to read. Possible values: A and B.
which
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.
base
The base address of the database. See details below.
compressed
Logical constant, if TRUE than the file is expected to be compressed by gzip. If url is NULL then a .gz suffix is added to the filename.
directed
Logical constant, whether to create a directed graph.

Value

  • A new graph object.

concept

Graph database

Details

graph.graphdb reads a graph from the graph database from an FTP or HTTP server or from a local copy. It has two modes of operation:

If the url argument is specified then it should the complete path to a local or remote graph database file. In this case we simply call read.graph with the proper arguments to read the file.

If url is NULL, and this is the default, then the filename is assembled from the base, prefix, type, nodes, pair and which arguments. See the documentation for the graph database at http://amalfi.dis.unina.it/graph/db/doc/graphdbat.html for the actual format of a graph database file and other information.

References

M. De Santo, P. Foggia, C. Sansone, M. Vento: A large database of graphs and its use for benchmarking graph isomorphism algorithms, Pattern Recognition Letters, Volume 24, Issue 8 (May 2003)

See Also

read.graph, graph.isomorphic.vf2

Examples

Run this code
g <- graph.graphdb(prefix="iso", type="r001", nodes=20, pair="A",
  which=10, compressed=TRUE)
g2 <- graph.graphdb(prefix="iso", type="r001", nodes=20, pair="B",
  which=10, compressed=TRUE)
graph.isomorphic.vf2(g, g2)g3 <- graph.graphdb(url="http://cneurocvs.rmki.kfki.hu/graphdb/gzip/iso/bvg/b06m/iso_b06m_m200.A09.gz")

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