[R] Gravity (spatial interaction) models in R

[Roger Bivand]

Melanie Murphy <mamurphy <at> turbonet.com> writes:

> 
> I was wondering if anyone has developed (or is developing) an
> implementation for gravity models (spatial interaction) in R.  I
> conducted several searches on the CRAN website with no luck.  Currently
> I am estimating parameters via linearization.

There isn't anything (yet) in the Spatial task view on CRAN, and I'm not aware
of the topic coming up on the R-sig-geo list either. The nearest sign of
transport planning is perhaps the emme2 package for interfacing EMME/2 software.
As you are aware, there are many almost equivalent ways of fitting gravity
models, so many R functions are feasible. But no dedicated functions so far, I'm
afraid - if I'm wrong, please let me know, and I'll update the task view.

Roger

> 
> Thank you in advance
> 
> Melanie Murphy
>