> I'm calculating the distance between two plain PointFields in the GIS > branch using the distance GeoQuerySet method [1] and I'm coming up > with some confusing results. >
I require more information before I can answer your inquiry: (1) What geographic fields are in your model, what type are they (e.g., PointField, etc.), and their SRID. (2) The geometry type of the parameter you're passing to `distance`, and its SRID. > The distance between nearby things is often about right, maybe off by > a mile or two. But the distance between farther locations is off by > quite a bit. The distance between Salt Lake City and Chicago is > reported as just over 10,000 miles, for example. My guess is that you're trying to calculate distances from a projected coordinate system to a geodetic point that is outside the valid range of your projection. For example, if I had a model in the projected coordinate system of SRID=32140 (only valid for South Texas[1]), and I attempted to calculate distances from my model to a WGS84 point referencing Denver, CO (SRID=4326) then I would get garbage distances returned because Denver is well outside the valid range for 32140. If I were to use a WGS84 point referencing San Antonio instead of Denver valid results would be returned. [1] http://spatialreference.org/ref/epsg/32140/ --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
