Hello,
I am unable to figure out why a certain processing algorithm (v.net.steiner) works fine in QGIS2, but not in QGIS3. I am using the same line and point layer with the same cost column. The input data as well as the cost column are the only parameters that I define, the others remain the default ones.
In QGIS2 the processing history looks like this:
processing.runalg(“grass7:v.net.steiner”,“C:/xxx/linesLayer.shp”,“C:/xxx/nodeLayer.shp”,50,2,“1-100000”,“boundary”,-1,False,“794057.939937,794307.889937,9833916.58837,9834082.13837”,-1,0.0001,0,None)
The result looks the following connecting the 3 nodes via the line layer.
In QGIS3 the processing history looks like this:
processing.run(“grass7:v.net.steiner”, {‘input’:‘C:/xxx/linesLayer.shp’,‘points’:‘C:/xxx/nodeLayer.shp’,‘threshold’:50,‘arc_type’:[0,1],‘terminal_cats’:‘1-100000’,‘acolumn’:‘boundary’,‘npoints’:-1,‘-g’:False,‘output’:‘G:/1_QGIS_Temp_files/processing_f8ef30794232406cb21d5d7cc1d06809/4774808dfe284dafafd9a15a9879a5c1/output.shp’,‘GRASS_REGION_PARAMETER’:None,‘GRASS_SNAP_TOLERANCE_PARAMETER’:-1,‘GRASS_MIN_AREA_PARAMETER’:0.0001,‘GRASS_OUTPUT_TYPE_PARAMETER’:0})
No result is created. The error messages indicate that the point layer cannot be used:
FEHLER: v.net.steiner: Sorry, is not a valid parameter
Importing the data to GRASS7 directly and running v.net.steiner there indicates the same, as I get the following error message:
Number of terminals: 0, ERROR: Nicht genügend Stationen (< 2)
I uploaded the subset of the line and point layer that I used here (https://share4land.itc.utwente.nl:5566/sharing/pfjsbL9G8).
Both QGIS2 and QGIS3 versions use GRASS7.4.
Any ideas on how to figure out further what the problem might be?
Best,
Sophie