This function returns an estimation of the optimal parameter value based on the average surface area of the locations (in square kilometer) according to the law. This estimation has only been tested on commuting data (in kilometer).
Arguments
- av_surf
a positive numeric value indicating the average surface area of the locations (in square kilometer).
- law
a character indicating which law to use (see Details).
Value
An estimation of the optimal parameter value based on the average surface area of the locations.
Details
The estimation is based on the 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"), the 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.
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