Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

i have a set of parcels in DWG file and i have the areas that should be in these parcels in an excel file, so i have to modify each parcel to match the area specified in the excel file with a moving the minimum of points of each parcel (polygone), i'm searching any tool to automate this process in GIS (autocad , arcgis , arcgis engine , postgis ..)

share|improve this question
Note that any software to produce cartograms will work. Because there is no unique solution, it would help to provide additional criteria (such as minimizing some measure of the maximum change that occurs among all parcels). However, automated changing of controlled data like parcel maps sounds like a really poor idea in general. – whuber Sep 21 '11 at 15:22
Agreed. Particularly with something like parcels. So they're all the right size now... is it OK that your processing has made the boundaries no longer touch? Probably not. – Paul Ramsey Sep 21 '11 at 19:24
up vote 4 down vote accepted

I agree with @whuber's comment that moving parcel geometry to try to match area values is a bad idea. Since GIS features and layers are only representative of "the real world" it is often difficult to make the digital geometry match the on-the-ground features.

To me, your best bet is to stick with the geometries that are provided in the DWG (which were likely created using coordinate geometry input, or COGO, from "raw" legal descriptions) and simply attach the Excel values to the GIS features as an additional field. If you want to help users differentiate between on-the-ground values and digital values, consider creating something like "GIS_Acres" and "Legal_Acres" fields.

Definition: Coordinate Geometry (COGO)- A method of defining geometric features through the input of bearing and distance measurements. Coordinate Geometry (COGO) functions are typically used by land surveyors to enter traverses around spatial features such as parcels, to calculate precise locations and boundaries sing distances and bearings from reference points, and to define curves using a point location, radius, arc-length, and so on.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

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