I have a geodjango model with fields
coverage = 10 * 1609.344 reference_point = Point(-72,45) #or some other lat lng class ServiceArea (geo_models.Model): center = geo_models.PointField(default=None, blank=True, null=True) radius = models.FloatField(default=floor(6 * 1609.344), null=True, blank=True) # in meters
I am user center and radius to store a circle representing a service area. I would like to query this to return all objects where the "center" is less than (coverage + radius) away from "reference_point".
Or to put it another way, filter based on any part of the circlular service area being within a certain distance of a reference point.
This is simple with polygonfields, where I can do something like
Although I haven't figured it out yet I imagine it would be possible to store the circles as polygons, and do the calculation as above, but this may have its own problems. And it is simpler for other reasons to just store coordinates and radius in the database to approximate circles.
I've tried using django.db.models.F, but it doesn't seem to work in this situation.
What do you guys think?