Ticket #1929 (closed defect: fixed)

Opened 10 months ago

Last modified 10 months ago

regression issue: ST_Polygon used to return simplest polygon

Reported by: robe Owned by: dustymugs
Priority: medium Milestone: PostGIS 2.1.0
Component: raster Version: trunk
Keywords: Cc:

Description

In 2.0, when I wrote the docs:  http://postgis.refractions.net/documentation/manual-svn/RT_ST_Polygon.html

ST_Polygon would return a polygon or multipolygon. Now I see it always seems to return a multipolygon even if that multipolygon only contains one polygon. The answer is different too, but I have to verify dataset is the same to be sure.

If polygon/multipolygon is intentional it should probably be flagged as such in the docs. Also docs are missing an enhanced flag to denote the change from partial plpgsql based to full faster C-based. Is that okay to put in or are you still working on things and want to wait.

Change History

Changed 10 months ago by robe

documented at r10086

Let's keep the multipolygon behavior. i like the fact that the type is now always the same. If people want a polygon they can do an ST_UnaryUnion wrap.

Changed 10 months ago by dustymugs

I actually prefer the multipolygon behavior as it guarantees that the output will always be multipolygon. Another thing that did change with the C version is that the code will validate that the union of the pixel polygons is valid and if not will call GEOS's make-valid function.

I'll double-check the changes you made in r0086 and add any revisions. Once I've done that, I'll close this ticket.

Changed 10 months ago by dustymugs

  • status changed from new to closed
  • resolution set to fixed

Additional tweaks in r10098.

Note: See TracTickets for help on using tickets.