Fairfax County, Virginia provides a Shapefile here which shows the boundaries of the tax maps as polygons. Each polygon simply consists of four corners, and what I'd like to do is create a table showing the map number and the coordinates of the corners, such as the following:

Map number, bottom-left, bottom-right, top-right, top-left
77-1, -77 32, -76 32, -76 33, -77 33

(though they aren't quite square like this)

I don't have access to ArcGIS software, but do have QGIS and OpenJUMP, and can install any other software that is freely available. I believe this should be very easy but I'm just missing something. Thanks!

1 Answer 1


In QGIS you can use "Extract nodes" to first get the corner points of your polygons. Then, using "Export/Add geometry columns" you can add x and y coordinates to those points. The results will be four lines of data though.

Another way is to copy paste the geometries from QGIS' map window into a text editor. You'll get the WKT representation of the polygons, e.g.

POLYGON((-0.971664 0.453443,-0.516714 0.827044,-0.245552 0.432353,-1.001793 -0.224462,-0.971664 0.453443))
  • 1
    Thanks, took me a minute to find those commands (they're under Vector->Geometry Tools). I could then open the attribute table and view the corners and their coordinates. I didn't see a way to dump the table other than copying and pasting. However it will take a little mashing to produce the format I need, since each corner is it's own row, and one corner is duplicated (I suppose it's the beginning and ending node). I suppose I can't expect these tools to give me the data in the exact format I want. Thanks again!
    – joshdoe
    Mar 9, 2011 at 1:28
  • The WKT representation should be closer to the format you were looking for. But any solution will require some postprocessing.
    – underdark
    Mar 9, 2011 at 7:20

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.