[QGIS-Developer] Frage

Raymond Nijssen r.nijssen at terglobo.nl
Mon Mar 23 05:21:00 PDT 2020


Hi Sebastian,

Here's a little python script that works on a vector layer containing 2 
lines. Just as an example.

Hope it helps,
Raymond




# calculates the maximum distance between 2 lines
# in the active vector layer

line_layer = iface.activeLayer()
nf = line_layer.featureCount()

if not nf == 2:
     print('layer must have 2 features')
else:

     feat1 = line_layer.getFeature(1)
     geom1 = feat1.geometry()
     feat2 = line_layer.getFeature(2)
     geom2 = feat2.geometry()

     max_dist = 0

     vert1 = geom1.vertices()
     for p1 in vert1:
         vert2 = geom2.vertices()
         for p2 in vert2:
             dist = p1.distance(p2)
             if dist > max_dist:
                 max_dist = dist
                 max_p1 = p1
                 max_p2 = p2

     if max_dist > 0:
         print('max distance: {})'.format(max_dist))
         print('LINESTRING({} {}, {} {})'.format(
             max_p1.x(), max_p1.y(), max_p2.x(), max_p2.y() ))





On 22-03-2020 16:13, Jorge Gustavo Rocha wrote:
> Hi Sebastian,
> 
> Are you looking for a function like ST_MaxDistance [1] available in
> PostGIS?
> 
> I'm not aware of such function in QGIS, but it can be implemented in PyQGIS.
> 
> Best regards,
> 
> Jorge Gustavo
> 
> [1] http://postgis.net/docs/ST_MaxDistance.html
> 
> On 22/03/20 13:50, Sebastian Hess wrote:
>> Sehr geehrte Damen und Herren,
>>   
>> ich benutze die QGis-version 3.12.0 und hätte ein Frage:
>>   
>> Gibt es in QGIs eine Funktion, mit der man den Punkt mit dem maximalen
>> Abstand zwischen zwei Lininen herausfnden kann, und dann den
>> dazugehörigen Wert des Abstandes in Metern erhält.
>>   
>> Mit freundlichen Grüßen
>> Sebastian Heß
>>
>> _______________________________________________
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>> QGIS-Developer at lists.osgeo.org
>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer
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>>
> 
> J. Gustavo
> 


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