Parameter file format

Parameter files (.params) describe the configuration space: which parameters exist, their domains, defaults, conditional activation, and forbidden combinations.

The format is identical to the original Ruby ParamILS param_reader.rb.

Discrete parameters

name {val1, val2, val3, ...} [default]

Example:

alpha {1.01, 1.066, 1.126, 1.189, 1.256, 1.326, 1.4} [1.189]
rho   {0, 0.17, 0.5, 1}                               [0.5]

Values are always strings. Numeric values are parsed by the target algorithm.

Conditional parameters

A conditional parameter is only active (included in the command line) when its parent has a specific value:

child {val1, val2} [default] | parent in {allowed1, allowed2}

Example:

noise_type {random, walk} [random]
noise_param {0.0, 0.1, 0.5} [0.1] | noise_type in {walk}

noise_param is only passed to the algorithm when noise_type = walk. Otherwise it is omitted from the command line.

Forbidden combinations

A forbidden combination prevents specific joint assignments from being evaluated:

{param1=val1, param2=val2, ...}

Example:

{alpha=1.01, rho=0}

Any configuration where alpha=1.01 and rho=0 simultaneously is skipped during search.

Comments

Lines starting with # and trailing #... are ignored:

# This is a comment
alpha {1.01, 1.189} [1.189]   # inline comment

Full example

# SAPS parameters
alpha {1.01, 1.066, 1.126, 1.189, 1.256, 1.326, 1.4} [1.189]
rho   {0, 0.17, 0.5, 1}                               [0.5]
ps    {0.0, 0.01, 0.05, 0.1, 0.2, 0.5}                [0.1]
wp    {0.0, 0.01, 0.05, 0.1, 0.2}                     [0.03]

# Forbidden: degenerate case
{alpha=1.01, rho=0}