Implementation of the Bouchitté-Todinca algorithm for finding optimal graph triangulations.
Triangulator can be used for finding an optimal solution for the following problems: The treewidth and minimum fill-in of a graph, the generalized hypertreewidth and fractional hypertreewidth of a hypergraph, the total table size of a Bayesian network.
Build the code with the makefile provided. This should create executable file main.
Triangulator reads the input graph from the standard input and outputs the optimal fill edges or tree decomposition to the standard output. Additional information, like the optimal graph parameter obtained is outputted to the standard error stream.
A basic example would be
./main -minfill < instances/anna.graph
You should use a flag to select the graph parameter that is optimized. Available options are:
- -treewidth : Treewidth of a graph
- -minfill : Minimum fill-in of a graph
- -hyper : Generalized hypertreewidth of a hypergraph
- -frachyper : Fractional hypertreewidth of a hypergraph
- -bayes : Total table size of a Bayesian network
There are also additional flags:
- -pmcprogress : Print information to stderr during the PMC enumeration phase.
- -k : Set an upper bound for the search. Triangulator will report the optimal solution or that the value of the optimal solution is higher than k. Use e.g.
-k=12Currently works only with treewidth and minimum fill-in.
Triangulator supports multiple graph formats. The graphs in directories
instances-bayes give examples of some supported formats.
For hypergraphs the format used in the CSP hypergraph library is supported.
For Bayesian networks the .bif, .dsc and .net formats are supported.
To use GLPK as the LP solver for Fractional hypertreewidth you need to modify
The output formats for hypergraphs and Bayesian networks are likely not very useful. Feel free to open an issue if there is an output format that would be useful for your project.