Curves

Oct 1, 2012 at 9:58 PM

We're interested in working with the PostGIS curve types (CIRCULARSTRING, etc). You've mentioned this isn't supported as there are possible issues with spatial operations. However, there's a line in the PostGIS GDO FAQ that says:

"If a table created by PostGIS tools contains geometries with curves, the arcs can both be read and writen by GeoMedia."

Is this FAQ statement correct?


I've tried creating tables with "geometry(Geometry,32054)" and a CIRCULARSTRING using PostGIS function ST_GeomFromText('...'), and when I "Add Legend" in Geomedia, nothing is displayed, and there's a "Curves (0)" in the map's legend entry.

Are there any plans to support arcs in Geomedia?

Oct 12, 2012 at 4:08 PM

Yes, the statement is correct, however, not all curve types have been tested. Can you provide the full SQL script to create the table and to populate it with data?

Thanks, Pavel

Oct 16, 2012 at 2:16 PM

Here's a simple one:

CREATE TABLE curves (id series, name text, geom geometry(MultiCurve,32054));

INSERT INTO curves (name, geom) VALUES ('a',ST_GeomFromText('MULTICURVE( (0 0, 5 5), CIRCULARSTRING(4 0, 4 4, 8 4) )',32054));

INSERT INTO curves (name, geom) VALUES ('b',ST_GeomFromText('MULTICURVE( CIRCULARSTRING(14 10, 14 14, 18 14, 21 14, 32 87) )',32054));

Oct 31, 2012 at 5:46 PM

Can you post an example that works for you?

Table creation and curve creation that subsequently *will* display in GeoMedia?

Nov 2, 2012 at 12:17 PM

The problem is most likely caused by PostGIS version. I've got the previous example and can see the problem in PostGIS 2.0. It will be fixed in next release, I hope during next week. Thanks, Pavel

Nov 7, 2012 at 5:43 PM

Tested very lightly so far - seems to be working on tables that are geometry(MultiCurve,32054).

Tables with geometry(MultiCurve) or geometry(Geometry,32054) displayed initially. Using the Move tool on them caused a "~ Method of ~ Cmd Failed" (something similar to that), and subsequently the curves disappear and the layer's Legend entry (num features) is decremented. I checked and they still exist in the PostgreSQL table.

Nov 19, 2012 at 5:09 PM

 

OK, I'll check and possibly fix this. Thanks, Pavel