PGAPack

The NEOS Server offers PGAPack (PGAPack Parallel Genetic Algorithm Library) for the solution of simple bound constrained optimization problems in AMPL format.

PGAPack was developed by David Levine of the Mathematics and Computer Science Division at Argonne National Laboratory. The PGAPack AMPL interface was developed by Ismael Vaz in order to benchmark the PSwarm solver with a set of problems.

For further information about PGAPack interface to AMPL, contact aivaz@dps.uminho.pt. For further information about PGAPack contact the PGAPack author.

The following is a list of options for PGAPack that the user may set via the AMPL input files. For example, option pgapack_options "maxfun=1000";

• crossover - PGASetCrossoverType (1=ONEPT, 2=TWOPT, 3=INIFORM)
• debug_level - PGASetDebugLevel (12=ENTERED, 13=EXIT, 80=MALLOC, 82=PRINTVAR, 22=SEND, 23=RECV)
• fitness - PGASetFitnessType (integer)
• ga_iter_value - PGASetMaxGAIterValue (integer)
• maxfun - Maximum number of objective function calls (integer)
• mutation - PGASetMutationType (1=RAW, 2=NORMAL, 3=RANKING)
• num_replace_value - PGASetNumReplaceValue (integer)
• pop_rep - PGASetPopReplaceType (1=BEST, 2=NOREP, 3=REP)
• pop_size - PGASetPopSize (integer)
• selection - PGASetSelectType (1=PROPOR, 2=SUS, 3=TOUR, 4=PTOU)

Using the NEOS Server for PGAPack/AMPL

The user must submit a model in AMPL format. Examples are provided in the examples section of the AMPL website.

The problem must be specified in a model file. A data file and commands files may also be provided. If the commands file is specified, it must contain the AMPL solve command; however, it must not contain the model or data commands. The model and data files are renamed internally by NEOS.

The commands file may include option settings for the solver. To specify solver options, add

  option pgapack_options 'OPTIONS';