Options in the Makefile

The Makefile has the following variables defined, that may need adjustment:

CC = gcc
FC = g77 
CFLAGS = -mcpu=i686 -Wall -malign-double -O6
LFLAGS = -lm

This Makefile works on a GNU/Linux system with the EGCS C and Fortran compilers.

You may wish to experiment with one more option. During the optimization process, two different heuristics can be used. They are chosen at compile-time by the two following defines:

#ROWORDER_RECORDER=1
ROWORDER_BIPORDER=1

Which one of the two defines that are uncommented will determine which heuristic is used. The ROWORDER_BIPORDER is much faster on larger systems, but the ROWORDER_RECORDER may give better results. When system sizes exceed about 20 x 20 or if the percentage of non-zeros exceeds 10% the ROWORDER_RECORDER usually run too slow to do any good. Experiment with this.

Run make to build the optimqr program. This sould give you the executable optimqr.

To optimize the 15 x 15 system described in the previous section, type the command optimqr system.size15. The arguments that can be given to optimqr are:

optimqr <system file> [acceptance factor] [output directory]

Where the argument enclosed in sharp brackets is a mandatory argument, and the two arguments in square brackets are optional arguments.

System File	This is the name of the file in which the system is described. This argument is mandatory.
Acceptance Factor	Since the search for ``good'' orderings use heuristics, and the heuristic used overshoots the estimated cost of the partial solution, we multiply the estimate from the heuristic with an ``acceptance factor''. The default value for the compensation factor is 0.68. A larger value may give worse results, since more possibly good branches in the search tree are discarded. A smaller value vill increase run-time of the optimizer. The default value has experimentally been found to be good, but you may wish to experiment here.
Output Directory	The optimizer generates a number of output files. The default is to save these files in the directory Output relative to the current working directory. You can specify an alternate output directory here.