ablation: Performs ablation between two configurations (from source to...
In irace: Iterated Racing for Automatic Algorithm Configuration

ablation

R Documentation

Performs ablation between two configurations (from source to target).

Description

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

Usage

ablation(
  iraceResults,
  src = 1L,
  target = NULL,
  ab_params = NULL,
  type = c("full", "racing"),
  nrep = 1L,
  seed = 1234567L,
  ablationLogFile = "log-ablation.Rdata",
  instancesFile = "train",
  ...
)

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.
`src`, `target`	`integer(1)\|character(1)` Source and target configuration IDs. By default, the first configuration ever evaluated (ID 1) is used as `src` and the best configuration found by irace is used as target. If the argument is a string, it is interpreted as the path to a file, with the format specified by `readConfigurationsFile()`, that contains the configuration.
`ab_params`	`character()` Specific parameter names to be used for the ablation. They must be in `parameters$names`. By default, use all parameters.
`type`	`"full"\|"racing"` Type of ablation to perform: `"full"` will execute each configuration on all `n_instances` to determine the best-performing one; `"racing"` will apply racing to find the best configurations.
`nrep`	`integer(1)` Number of replications per instance used in `"full"` ablation. When `nrep > 1`, each configuration will be executed `nrep` times on each instance with different random seeds.
`seed`	`integer(1)` Integer value to use as seed for the random number generation.
`ablationLogFile`	`character(1)` Log file to save the ablation log. If `NULL`, the results are not saved to a file.
`instancesFile`	`character(1)` Instances file used for ablation: `'train'`, `'test'` or a filename containing the list of instances.
`...`	Further arguments to override scenario settings, e.g., `debugLevel`, `parallel`, etc.

Value

A list containing the following elements:

allConfigurations: Configurations tested in the ablation.
state: State of the ablation process.
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.
complete: TRUE if the ablation process was completed.

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


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

irace documentation built on April 3, 2025, 10:03 p.m.