$Id: itm-doc.txt,v 1.1 1996/10/04 13:29:13 ewz Exp $ Name: itm Function: Driver to create flat random graphs and two forms of hierarchical graphs (N-level and transit-stub). See models.ps for a more complete description of the methods. This file describes the syntax and (limited) semantics of the parameter specification file. Usage: itm .... Details: File Format ----------- Each argument is a file containing ONE set of specs for graph generation. Such a file has the following format: [# comment line] [] is one of: "geo": flat random graph "hier": N-level hierarchical graph "ts": transit-stub graph : number of graphs of specified type to generate : initial random number seed; optional Any line preceeded by # is a comment and is ignored by itm. Method-dependent Parameters --------------------------- All of the methods make use of the following line, which specifies the parameters for a flat random graph. Six different types of flat random graphs are supported. (See models.ps for more detail on parameters and edge generation methods.) ::= [ ] : number of nodes in graph : one-sided dimension of space in which nodes are distributed : method for generating edges; valid range 1..6 1: Waxman 1 2: Waxman 2 3: Pure random 4: Doar-Leslie 5: Exponential 6: Locality : random graph parameter (0.0 : random graph parameter (0.0 : random graph parameter (0.0 The are as follows: ::= ::= + {one per number of levels} : number of levels in hierarchy : method of resolving edges (NOTE: probably should just use method 0) 0: random 1: use non-leaf node of smallest degree 2: use node of smallest degree 3: use first node with degree less than : see above ::= {top-level parameters} {transit domain parameters} {stub domain parameters} : avg number of stub domains attached per transit node : number of extra transit-stub edges : number of extra stub-stub edges Output File Naming Convention: ------------------------------ The i'th graph created with the parameters from file "arg" is placed in file "arg-i.gb", where the first value of i is zero. Example of Usage: ----------------- The following is a valid specification file called r10: # [] # [] [] geo 3 10 10 3 .2 If we run 'itm r10' then three pure random graphs of 10 nodes each will be created. The nodes of each graph will be generated in a 10 by 10 (logical) grid. The probability of an edge is 0.2, as given by the parameter; and are not needed for this method. The output files will be named: r10-0.gb, r10-1.gb, r10-2.gb. (This specification file and the resulting output files can be found in sample-graphs/rand/r10.) Another Example of Usage: ------------------------- The following is a valid specification file called t100: # [] # # [] [] # number of nodes = 1x4x(1+3x8) = 100 ts 10 47 3 0 0 1 20 3 1.0 4 20 3 0.6 8 10 3 0.42 If we run 'itm t100', then 10 transit-stub graphs of 100 nodes each will be created, starting with initial seed 47. Each graph will have three stub domains per transit node, with no extra transit-stub or stub-stub edges. The line "1 20 3 1.0" says that there will be one transit domain. The next line "4 20 3 0.6" specifies transit domains have (on average) four nodes, and an edge between each pair of nodes with probability 0.6. The last line "8 10 3 0.42" says that each stub domain will have (on average) eight nodes, and edge probability 0.42. The graphs will be named t100-[0-9].gb.
