graph.graphdb             package:igraph             R Documentation

_L_o_a_d _a _g_r_a_p_h _f_r_o_m _t_h_e _g_r_a_p_h _d_a_t_a_b_a_s_e _f_o_r _t_e_s_t_i_n_g _g_r_a_p_h
_i_s_o_m_o_r_p_h_i_s_m.

_D_e_s_c_r_i_p_t_i_o_n:

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

_U_s_a_g_e:

     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) 

_A_r_g_u_m_e_n_t_s:

     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', 'm3Dr2', 'm3Dr4', 'm3Dr6', 'm4D',
          'm4Dr2', 'm4Dr4', 'm4Dr6', 'b03',  'b03m', 'b06', 'b06m',
          'b09', 'b09m'. 

   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.

_D_e_t_a_i_l_s:

     '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 <URL:
     http://amalfi.dis.unina.it/graph/db/doc/graphdbat.html> for the
     actual format of a graph database file and other information.

_V_a_l_u_e:

     A new graph object.

_A_u_t_h_o_r(_s):

     Gabor Csardi csardi@rmki.kfki.hu

_R_e_f_e_r_e_n_c_e_s:

     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)

_S_e_e _A_l_s_o:

     'read.graph', 'graph.isomorphic.vf2'

_E_x_a_m_p_l_e_s:

     ## Not run: 
     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")
     ## End(Not run)

