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Automatic calibration of trip distribution laws' parameter

Source: R/calib_param.R
calib_param.Rd

This function returns an estimate of the optimal parameter value based on the average surface area of the locations (in square kilometers) according to the law. This estimation has only been tested on commuting data (in kilometers).

Usage

calib_param(av_surf, law = "NGravExp")

Arguments

av_surf

A positive numeric value indicating the average surface area of the locations (in square kilometers).

law

A character string indicating which law to use (see Details).

Value

An estimate of the optimal parameter value based on the average surface area of the locations.

Details

The estimation is based on Figure 8 in Lenormand et al. (2016) for four types of laws: the normalized gravity law with an exponential distance decay function (law = "NGravExp"), the normalized gravity law with a power distance decay function (law = "NGravPow"), Schneider's intervening opportunities law (law = "Schneider"), and the extended radiation law (law = "RadExt").

References

Lenormand M, Bassolas A, Ramasco JJ (2016) Systematic comparison of trip distribution laws and models. Journal of Transport Geography 51, 158-169.

See also

Associated functions: extract_opportunities() extract_spatial_information() check_format_names()

Author

Maxime Lenormand (maxime.lenormand@inrae.fr)

Examples

data(county)

res <- extract_spatial_information(county, id = "ID")
av_surf <- mean(res$surface)

calib_param(av_surf = av_surf, law = "NGravExp")
#> [1] 0.08521097
calib_param(av_surf = av_surf, law = "NGravPow")
#> [1] 3.295941
calib_param(av_surf = av_surf, law = "Schneider")
#> [1] 2.475339e-06
calib_param(av_surf = av_surf, law = "RadExt")
#> [1] 1.299361