Drivetime analyses, pgRouting

We’ve got some quick and dirty pgRouting-based code up on github. I say quick and dirty because it directly references the table names in both of the functions. I hope to fix this in the future. The objective with this code is to input a point, use a nearest neighbor search to find the nearest intersection, and from that calculate a drive time alpha shape. … Continue reading Drivetime analyses, pgRouting

Realistic biking distances, pgRouting

In an upcoming recipe (another one for the cutting room floor), we’ll play a bit with realistic biking distances, as compared with a 5-mile buffer (light grey), a 5-mile driving distance (dark grey), and a 5-mile biking-on-roads-with-speed-limits-under-40mph (purplish). This is just a teaser for mapbaker… . Continue reading Realistic biking distances, pgRouting

PostGIS Cookbook Promises

So, as we’re are in the final edits of the PostGIS Cookbook, there are some recipes that have ended up on the cutting room floor.  Several of these will end up on this blog: Amongst those that will end up in the alternate pipeline, and thus ultimately in GitHub, will be a project called pgOrthogonalize, similar to the functionality in Potlatch2 and iD to square … Continue reading PostGIS Cookbook Promises