I'm trying to create a visual map in QGIS 2.4 of the approximate distribution of journey origin points using a shapefile of UK postcode sectors, layer joined to a table with a column giving the number of journey origins in each sector. Using the Vector > Research Tools > Random Points menu tool, I can select the Input boundary layer and click the 'Use value from input field' radio button, but the pull-down menu to select the required field does not seem to work. If I then specify the Output Shapefile name and target location , I get an error message - "Errors: The following features IDs couldn't be calculated due to conversion error: 335, 335". To confirm, QGIS does display random points if I specify the density or a specific number of points using the first two 'Stratified Sampling' Designs for individual polygs.
Subscribe to:
Post Comments (Atom)
-
Im having a problem toggling the visibility of map layers in pyqgis (2.4). I have a simple interface, just the map canvas, no legend, and ba...
-
I have a single table of over 1000 polygons in postgreSQL (with PostGIS), and I have a field "evaluation_type" that only receives ...
-
I want to create a center line for a river (polygon). I thought about simply creating a new line manually, but it would be a long and imperf...
No comments:
Post a Comment