In order to compile exactcolors you need an LP-solver. Either one of
- Gurobi [34].*.*
- CPLEX 12.[23] , or
- Qsopt
will work.
1. Preparing the Makefile for the LP-Solver
For Gurobi, the GUPATH variable in the Makefile has to point to
to the os-dependent subdir in your Gurobi-installation. E.g.
you set
export GUROBI_HOME=<path-to-gurobi-installation>/gurobi461/linux64/ ,
uncomment the line
GUPATH=$(GUROBI_HOME)
in the Makefile and comment out the lines were CPLEXPATH and QSPATH.
For CPLEX, the CPLEXPATH variable needs to point to the cplex installation.
E.g. you can set
export CPLEX_HOME=<path-to-cplex-installation>/cplex/cplex123/cplex/
and uncomment the line
CPLEXPATH=$(CPLEX_HOME)
in the Makefile and comment out the lines were GUPATH and QSPATH are defined.
Depending on your installation you might also need to adapt the
LPLIB path in the Makefile.
For QSOPT, QSPATH variable in the Makefile need to point to the qsopt installation.
E.g. you can set QSOPT_PATH=<path-to-qsopt-headers-and-lib>/
and uncomment the line
QSPATH=$(QSOPT_HOME)
in the Makefile and comment out the lines were GUPATH and QSPATH are defined.
2. Compiling
For compiling you simply call
make
For parallel compiling via 'make -j' you may have to call 'make -j' twice, because
some c-files are generated during compilation and may not be ready on time.
This will build the programs:
- 'color', the main B&P program for graph coloring
- 'stable', can be used to call Gurobi or Cplex as an MWSS-solver.
- 'mwis_sewell/sewell' (Algorithm 1 in "Held, Cook, and Sewell:yes
Safe Lower Bounds for Graph Coloring. IPCO2011"),
an adaption of Sewell's combinatorial stable set algorithm.
- 'complement' to construct the complement of a graph
- 'partition' to find dense subgraphs with a given number of vertices.
Special commands for the parallel B&P framework:
- 'color_worker' a worker for solving a B&P-node.
When color is called with the '-p' option, it will solve only the root LP
and then act as a boss for the parallel B&P code. To this end it
will maintain a job queue. Workers (color_worker) will ask for jobs and
submit results.
The program color_worker can be started on any machine that as network access
to the machine were the boss 'color' runs by
'color_worker <hostname of boss-machine>'
ATTENTION: The boss listens to the port 24870 as specified in bbsafe.h!
Make sure that this port is available on the machine you use for the boss
and that you start at most one boss on a host!
- 'color_jobkiller', can be used to notify the master program that the branch-and-bound
node with the given Id should be resubmitted to the job-queue, because the
worker died.
3. Help
For all programs if you just call the program without parameters you will get a help.
4. Using exactcolors through the C API, which is located in color.h
Create a graph with ncount nodes, ecount vertices where edges are stored in an edge list, which
consists of 2*ecount entries and the i-th edge has endpoint elist[2*i] and elist[2*i+1].
REMARK: The graph has to be connected!
Step 1: Call
int COLORproblem_init_with_graph(COLORproblem* problem, int ncount,int ecount, const int elist[]);
Step 2: Call
int COLORexact_coloring(COLORproblem* problem,
int *ncolors,
COLORset **colorclasses);
to retrieve the number of colors (ncolors) and the actual coloring (colorclasses).
Step 3: Release all data
void COLORproblem_free(problem);
void COLORfree_sets (colorclasse, ncolors);
5. Using the combinatorial stable set solver through the C API.
The API & documentation can be found in mwis_sewell/mwss_ext.h.
The library is mwis_sewell/libsewell.a