parse.control: Parse control parameter for highway assignment

Description Usage Arguments Details Value Author(s) See Also

Description

Extract control parameters for highway assignment, supplying defaults when available.

Usage

1
parse.control(control,control.element,default.value=NULL)

Arguments

control

Assignment algorithm control parameters (a named list)

control.element

Parameter to retrieve, a character string

default.value

Default value to supply if control parameter is not set (if NULL, global defaults apply if availble; see details)

Details

This function will generally only be of interest to the developers of new highway assignment algorithms.

parse.control extracts a parameter from the control list typically provided to the highway.assign function. Certain parameters have global defaults, which may be overridden by a local default if the default parameter is supplied. The global defaults are as follows:

min.relative.gap 1e-4 Target for relative gap statistic
max.iter 100 Maximum iteration, except 4 for method=“MSA”)
max.elapsed 3600 Maximum time to run after the algorithm starts
opt.tol .Machine$double.eps^0.5 Tolerance for internal line searches.
verbose 1 Debugging level (higher numbers may generate more output; 0 for silent)
log FALSE If true, save a data.frame with the equilibrium statistics from each iteration

Any parameter for which no default is provided will return NULL when requested.

Arbitrary additional parameters may be defined. The control parameter is just a named list of values, and the function simply looks up the name and returns the corresponding element. It differs from simple list indexing in that it can provide a default value.

Value

parse.control returns a value for the named highway assignment control parameter

Author(s)

Jeremy Raw

See Also

highway.assign


travelr documentation built on May 2, 2019, 5:17 p.m.