Tag Info

New answers tagged

1

I haven't used that particular tool but the results look fairly typical of unsupervised snapping when the line vertex order doesn't respect the street topology and the geometric accuracy is poor. Not sure if by merge you simply mean create a topologically connected set of roads or merging parallel dual carriageway. But one option is to buffer with merge ...


2

Use the GeoServer SQL view feature, and SQL's ST_Project like, SELECT id, ST_SetSRID(ST_MakeLine( ST_MakePoint(lon,lat), ST_Project( ST_SetSRID(ST_MakePoint(lon,lat),4326)::geography, distance, pi()*azimuth/180.0)::geometry ),4326) AS geom FROM mytable; If you have long lines and want to plot them as great circles on a ...


2

Perhaps you can do it with some of the CAD plugins of QGIS. For sure you can do it with Kosmo GIS http://opengis.es/ Select to linestrings which should be extended and use the Expand lines until crossing tool from the CAD toolbox. CAD Tools extension must be activated first from the Extension manager. Click on the map. For the second case use another ...


0

If you're only looking to get the location of the lowest or highest point on the line then this is how I would go about it. Set up your point file and get z values from the dem. Extract your attribute table to excel and use a lookup to match your max/min z value (whichever you are looking for) for each line to the appropriate x and y values. You can then ...


1

Replace test.csv with the correct filename and paste the following code into the Python console. Note, that in your csv Lat=y comes before Lon=x. # specify your csv-file csvFile = "G:/test.csv" # create an empty memory layer for polylines layer = QgsVectorLayer('LineString?crs=EPSG:4326', 'Connected', 'memory') prov = layer.dataProvider() # add layer to ...


1

It is probably possible with GDAL but not extremely easy. Everything that can be done with SQL in SpatiaLite can also be done with GDAL http://www.gdal.org/ogr_sql_sqlite.html and this query could be used as starting point: ogrinfo -dialect sqlite test.shp -sql "select attr, st_union(geometry) from test group by attr" However, the query creates one ...



Top 50 recent answers are included