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I've got some old maps in dxf format. QGIS imports them correctly but with a nonsense scale. It can export the data it gets to shp of course. Does anyone know how to rescale vector data so it can be related to other maps? It doesn't have to be done in QGIS as long as the method is open source and it works on a format QGIS can handle (SHP is best, of course).

Note that there seem to be two scales in SHP: the data I hand-imported using WKT shows the correct scale on the mouse, but the map scale indicated is nonsense, and print composer is affected the same way. I'd like to correct both types of problem.

Germán Carrillo
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johnsankey
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  • Possible duplicate of: http://gis.stackexchange.com/questions/42421/dxf-to-georeferenced-shp http://gis.stackexchange.com/questions/22691/how-to-georeference-a-dxf – AndreJ May 26 '13 at 08:54
  • qgsAffine doesn't work on a Mac. This isn't georeferencing, it's scaling which is totally different. – johnsankey May 26 '13 at 15:46

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This is called rubbersheeting. Also georeferncing.
Be sure to choose a crs that is compatible with the original drawing system.
In other words you don't want to georeference a map drawn in UTM to lat lon.
Essentially you want pick a system you can simply move, scale, and rotate the original data to.

Brad Nesom
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