psRace function

Post-selection race

psRace performs a post-selection race of a set of configurations.

psRace(
  iraceResults,
  max_experiments,
  conf_ids = NULL,
  iteration_elites = FALSE,
  psrace_logFile = NULL
)

Arguments

• iraceResults: list()|character(1)

  Object created by irace and typically saved in the log file irace.Rdata. If a character string is given, then it is interpreted as the path to the log file from which the iraceResults object will be loaded.

• max_experiments: numeric(1)

  Number of experiments for the post-selection race. If it is equal to or smaller than 1, then it is a fraction of the total budget given by iraceResults$scenario$maxExperiments or iraceResults$scenario$maxTime / iraceResults$state$boundEstimate.

• conf_ids: IDs of the configurations in iraceResults$allConfigurations to be used for the post-selection. If NULL, then the configurations are automatically selected.

• iteration_elites: If FALSE, give priority to selecting the configurations that were elite in the last iteration. If TRUE, select from all elite configurations of all iterations. This parameter only has an effect when conf_ids is not NULL.

• psrace_logFile: character(1)

  Log file to save the post-selection race log. If NULL, the log is saved in iraceResults$scenario$logFile.

Returns

The elite configurations after the post-selection. In addition, if iraceResults$scenario$logFile is defined, it saves an updated copy of iraceResults in that file, where iraceResults$psrace_log is a list with the following elements:

• configurations: Configurations used in the post-selection race.
• instances: Data frame with the instances used in the post-selection race. First column has the instances IDs from iraceResults$scenario$instances, second column the seed assigned to the instance.
• max_experiments: Configuration budget assigned to the post-selection race.
• experiments: Matrix of results generated by the post-selection race, in the same format as the matrix iraceResults$experiments. Column names are the configuration IDs and row names are the instance IDs.
• elites: Best configurations found in the experiments.

Examples

irace_log <- read_logfile(system.file(package="irace", "exdata", "sann.rda"))
  # Use a temporary file to not change the original "sann.rda".
  psrace_logFile <- withr::local_tempfile(fileext = ".Rdata")
  # Execute the post-selection after the execution of irace. Use 10% of the total budget.
  psRace(irace_log, max_experiments=0.1, psrace_logFile = psrace_logFile)
  # Print psrace_log
  irace_log <- read_logfile(psrace_logFile)
  str(irace_log$psrace_log)

Author(s)

Leslie Pérez Cáceres and Manuel López-Ibáñez