Hi Ian, Thanks for the reply.
On Saturday, September 5, 2015 at 11:53:39 AM UTC-4, Ian McCullough wrote: > > Is there some compelling reason you wouldn't just install the PostGIS > extensions? Assuming there is... > There is; I can't use any of the functionality. My use case is astronomical data where all values are points on a sphere. I can't use the various projections that GIS provides. I investigated the possibility of using GIS tools for astronomical data a few years back, but found it wasn't really appropriate. I actually came across this which I found amusing: http://lists.osgeo.org/pipermail/postgis-devel/2009-March/005184.html > Actually, now that I think about it, since you won't be able to use them > in query expressions anyway, there's probably no reason to go to the extra > effort of hybrid properties; just make a pure python property to do the > conversion between the mapped TEXT|BLOB column and the Geometry types. > PostrgreSQL has a native "polygon" data type that I'd like to use: http://www.postgresql.org/docs/current/static/datatype-geometric.html There is a library that is specifically designed for astronomical data (which indexes points on a sphere): https://github.com/segasai/q3c and uses the polygon data type in this function: q3c_poly_query(ra, dec, poly) -- returns true if ra, dec is within the postgresql polygon poly. This is all I really need. I imagine my class will look something like this: class Field(Base): __tablename__ = 'field' __table_args__ = {'autoload' : True} polygon_column = ??? Where I can do: f = Field() f.polygon = ??? I just don't know what to put into the '???'s. Thanks, Demitri -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
