R: Performs ablation between two configurations.

ablation {irace} | R Documentation

## Performs ablation between two configurations.

### Description

Ablation is a method for analyzing the differences between two configurations.

### Usage

    ablation(iraceLogFile = NULL, iraceResults = NULL, src = NULL,
      target = NULL, ab.params = NULL, n.instances = NULL,
      type = "full", seed = 1234567,
      ablationLogFile = "log-ablation.Rdata", pdf.file = NULL,
      pdf.width = 20, mar = c(12, 5, 4, 1), debugLevel = NULL)

### Arguments

`iraceLogFile` | Log file created by irace, this file must contain the `iraceResults` object.
`iraceResults` | Object created by irace and saved in `scenario$logFile`.
`src, target` | Source and target configuration IDs. If `NULL`, then the first configuration ever evaluated is used as source and the best configuration found is used as target.
`ab.params` | Parameter names to be used for the ablation. They must be in parameters$names.
`n.instances` | Number of instances to be used for the "full" ablation, if not provided firstTest instances are used.
`type` | Type of ablation to perform, "full" will execute all instances in the configurations to determine the best performing, "racing" will apply racing to find the best configurations.
`seed` | Numerical value to use as seed for the random number generation.
`ablationLogFile` | Log file to save the ablation log.
`pdf.file` | Prefix that will be used to save the plot file of the ablation results.
`pdf.width` | Width provided to create the pdf file.
`mar` | Vector with the margins for the ablation plot.
`debugLevel` | (`integer(1)`) Larger values produce more verbose output.

### Value

A list containing the following elements:

configurations

  Configurations tested in the ablation.

instances

  A matrix with the instances used in the experiments. First column has the instances IDs from `iraceResults$scenario$instances`, second column the seed assigned to the instance.

experiments

  A matrix with the results of the experiments (columns are configurations, rows are instances).

scenario

  Scenario object with the settings used for the experiments.

trajectory

  IDs of the best configurations at each step of the ablation.

best

  Best configuration found in the experiments.

### Author(s)

Leslie Pérez Cáceres and Manuel López-Ibáñez

### References

C. Fawcett and H. H. Hoos. Analysing differences between algorithm configurations through ablation. Journal of Heuristics, 22(4):431–458, 2016.

### Examples

    irace.logfile <- file.path(system.file(package="irace"), "exdata", "sann.rda")
    load(irace.logfile)
    # Execute ablation between the first and the best configuration found by irace.
    ablation(iraceResults = iraceResults, ablationLogFile = NULL)
    # Execute ablation between two selected configurations, and selecting only a
    # subset of parameters, directly reading the setup from the irace log file.
    ablation(iraceLogFile = irace.logfile, src = 1, target = 10,
             ab.params = c("temp"), ablationLogFile = NULL)

[Package irace version 3.4.1 Index]