Nice work Sophia. In the same vein, it would be cool to see time-to-travel projections. Rural areas would stay more or less the same (no congestion), but urban areas with traffic problems would become gigantic. When I was recruiting last year, we had outside recruiting help in Chicago, and they just didn't understand that in LA, going 30 miles in rush hour can take up to 1-2 hrs.
Cheers, nym On Fri, Nov 7, 2008 at 12:57 PM, sophia parafina <[EMAIL PROTECTED]> wrote: > To clarify, I meant that if you have a origin/destination data of > travel costs you would have to conflate that data to a polygonal > dataset. > > As an example, I just grabbed the roads file from Geocommons as a > proxy for the travel cost with the very simplistic assumption that > more roads results in lower travel costs. > > I agree that weighted graphs would be a better visualization and more > commonly used to display OD types of data. > > sophia > > On Fri, Nov 7, 2008 at 3:29 PM, Christian Willmes > <[EMAIL PROTECTED]> wrote: >> sophia parafina schrieb: >>> http://iaddemo.erdas.com/Map.png >>> >> very cool! :-) >> >> But I don't get this: >>> If you want to do travel cost between cities you will need to conflate >>> you values to a polygon layer of administrative boundaries, since the >>> algorithm and scapetoad only works on polygons. So its definitely >>> most doable. >>> >> How can I derive travel cost from roads per area? >> Am I right, that you want to derive cost from the density distribution >> of roads per area? >> If the density between two points is low the cost is high and if the >> density between two points is high the cost is low? So far so good. >> But what if you have for example a highway through a very large area. >> The points along this highway would be accessible far better than the >> points in this area not connected directly to this one highway, but this >> other points would get the same cost values to access them, because they >> are in the same area unit. >> So in the moment I think you cant make good assumptions about travel >> cost from density distributions. Wheighted graphs are the better model >> for that question I think, also for the visualization of it... ;-) >> >> regards >> Christian >> >> _______________________________________________ >> Geowanking mailing list >> [email protected] >> http://geowanking.org/mailman/listinfo/geowanking_geowanking.org >> > > _______________________________________________ > Geowanking mailing list > [email protected] > http://geowanking.org/mailman/listinfo/geowanking_geowanking.org > _______________________________________________ Geowanking mailing list [email protected] http://geowanking.org/mailman/listinfo/geowanking_geowanking.org
