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I am hoping to create a point grid over the city of Edmonton. My workflow is:

  1. Import a KML of Edmonton neighborhoods from here
  2. Save the layer as a SHP
  3. Delete the layer and load the SHP
  4. Define the layer and project CRS as NAD 83 (HARN)
  5. Use the Vector > Research Tool > Regular Points tool to generate a grid of points over the geometry with a spacing of 500m.
  6. Save the output and load into the project.
  7. The output is a single point to the NW of the neighbourhood polygons.

I have been around this several time and am at a loss. Thank you!

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1 Answer

up vote 7 down vote accepted

It looks like you're using a geographic coordinate system instead of a projected coordinate system. Because NAD83 (HARN) uses degrees as the units, when you type in 500 in the grid spacing, it's using a spacing of 500 degrees, which is huge. You'll need to reproject the data to a more suitable projected coordinate system which uses metres such as UTM Zone 12N. Once you use that coordinate system, you should be able to use the tool without any trouble.

This is the result I got: enter image description here

Note, I live in Australia and I don't know which coordinate systems are most common for use in Canada.

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This looks EXACTLY like what I want. Thanks for the advise! Other than changing the projection (which makes sense), did you modify the workflow that I posted? –  Matt Dance Oct 8 '12 at 4:38
    
Not really. However, you can select the projection when you save out the shapefile. –  Fezter Oct 8 '12 at 5:42
    
Thanks Fezter for your help. Much appreciated! –  Matt Dance Oct 8 '12 at 14:40
    
I got it to work, but there seems to be some sort of conflict between the plug-ins. As an experiment when I first loaded QGIS, I loaded all of the plugins available from the Plugins > Manage Plugins menu. From that time I could not get the Vector > Research Tools to work. This time I unloaded all of the plugins, loaded only the fTools, and voila, the grid analysis worked. –  Matt Dance Oct 10 '12 at 3:03
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