Questions tagged [circularstring]
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10 questions
2 votes
1 answer
178 views
Working with CIRCULARSTRING in OGR's sqlite dialect
ogrinfo ":memory:" -dialect sqlite -sql "SELECT ST_GeomFromText('Point(1 2)')" gives me a dataset with a geometry column: INFO: Open of `:memory:' using driver `SQLite' ...
- 12.4k
5 votes
1 answer
169 views
Measuring distance between wavey lines/points in QGIS
In I want to design meandering lines on a plot at 5m distance apart. I am using the circular string tool so it's all by hand, ideally, they would be identical lines with a consistent 5m distance. How ...
- 141
5 votes
1 answer
384 views
Identifying polygons with arcs using QGIS
I have a polygon layer where there may be polygons and circular arcs as in the image. How can I identify the polygons which have those arcs parts?
- 1,616
0 votes
0 answers
89 views
JavaScript libraries for converting curves to/from EWKT and GeoJSON
Are there any JavaScript libraries that can convert EWKT/WKT curve geometries (as defined by PostGIS) to GeoJSON or similar? That is, libraries that generate a linear approximation of a CIRCULARSTRING ...
- 5,800
1 vote
0 answers
91 views
Get the measure M along a CircularStringM in PostGIS without first converting to a LineStringM
I've been struggling to get PostGIS 2.5 to run any linear referencing functions on geometry containing curves (CircularStringM, CompoundCurveM for example). Is it possible to get the measure M along ...
- 3,731
3 votes
1 answer
401 views
Adding filled circular rings (digitized) in vector layer
I digitize different habitats in one nature reserve. There was 40 ponds - I use "add circular string" option to give them a nice rounded shape. When I finish this 40 ponds I was instructed ...
- 101
1 vote
1 answer
66 views
Changing date format in field name from d2000_5000 to Dddmmyyyy? [closed]
I am trying to change the name of a field by using Python code where the current name is in the format (e.g.) d2000_5000, and 5000 is the decimal year (0,5 y) added to 2000. So i think that this can ...
- 25
5 votes
3 answers
3k views
ST_MakeLine equivalent for CIRCULARSTRING in PostGIS
I'd like to make a CIRCULARSTRING in PostGIS 2.0.0 out of points that are calculated as part of the query (rather than constants). For a LINESTRING I can do this using ST_MakeLine(). Is there an ...
- 755
9 votes
2 answers
2k views
Storing GML surface in PostGIS
I'm using PostGIS 2.0.0 and would like to store a GML Surface in a way that allows calculating intersections between that surface and various points and lines. In my case, the Surface will have one ...
- 755
5 votes
1 answer
2k views
How to draw or edit curved lines in free GIS?
I'm searching informations about drawing simple curved arrow lines into free GIS like QGIS, in this problem data geometry is CIRCULARSTRING ( a type which exists in latest postgis version) It seems ...
- 237