Hot answers tagged vector
Most probably you have set the CRS not correctly. Set CRS for Layer is NOT the right method, as it will not reproject the coordinates as you wish. Normally you don't jave to regard the different CRS, when you have On-the-fly-reprojection enabled. Please rightclick on each layer -> Properties, Metadata tab. There you can read what extent the layers have in ...
One possible reason for your error could be the fact that your edit is not saved when you compute the full length. Otherwise you should have the new length and the new "end" from your script. If this is not the case and you want to get rid of your extra vertices (because your script is based on a count of the vertices, for instance), you can use simplify ...
Well re-vectorization doesn't seem to be the key to a good solution here. As @Andre points out, the OSM Openlayers plugin just adds a raster layer. You can pick an OSM map (as cyclemap) that is postprocessed to include height contour lines, but in general height data (DEM) aren't part of the (current) OSM data model. So the contour lines are derived from ...
Please check the manual page of v.in.ascii to import points or GPS import (just see all import options in Menu -> File -> Import. However, for r.viewshed you give the coordinate pair simply as parameter. If you want to calculate several viewsheds, run it in a loop via a script.
If you don't like the plugin, fetch the OSM data you need with Overpass API, and add the result to QGIS with Add Vector Layer (enabeling All files filter). QGIS 2.0 uses GDAL 1.10's ogr2ogr OSM importer which does a good job. Relation support seems to be better than the plugin does at the moment. Just make sure you download ways and relations completely, ...
With the release of GDAL 1.10 this is now possible. It is done by performing a basic transformation in ogr2ogr and supplying the control points in the -gcp tag. http://www.gdal.org/ogr2ogr.html For a guide please see: http://gisforthought.com/georeferencing-vector-data-using-qgis-and-ogr2ogr/
Only top voted, non community-wiki answers of a minimum length are eligible