Take the 2-minute tour ×
Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. It's 100% free, no registration required.

I'm trying to split polygons into equal areas. While fishnet sort of works; the areas I'm trying to split don't touch; they're national parks. Fishnet spans the whole area, not just the polygons in question. Ultimately, I'm searching for a method to split polygons into a user-given number of equal area polygons.

I've read everything I can about the Huber methods to do this in ArcView, but without access to that (or experience with it) this isn't the answer for me.

Thanks very much.

share|improve this question

closed as unclear what you're asking by underdark Apr 26 at 21:49

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question.If this question can be reworded to fit the rules in the help center, please edit the question.

    
Have you considered this similar question: gis.stackexchange.com/questions/5300/… –  dassouki Jan 24 '11 at 20:52
    
Are the national parks polygons or multipolygons? How would you like those to be handled? –  underdark Jan 24 '11 at 21:45
1  
I have tried to describe the algorithm in a non-AV centric way (in the link provided by @dassouki). It will work in any GIS that supports scripting where you can (a) implement a 1D root finding algorithm, (b) clip polygons to rectangles, and (c) compute the area of a polygon. (A variant replaces (b) by (b') internally buffer polygons by specified amounts. This will dissect polygons into pseudo-concentric rings of specified area.) –  whuber Jan 25 '11 at 14:37
1  
@MBarretts Read sections 9.0 - 9.3 of Numerical Recipes; this will teach you all you need to know about root finding. nr.com/bookreader_chooser.html . I am curious about how "fishnet works," because as far as I can tell that just coarsely grids your polygons: something has to happen afterwards to effect the splitting. –  whuber Feb 2 '11 at 16:51
1  
@mbarretts, you say what software you don't have, Arcview, but you don't say what you do have. Also do you mean each split poly has to have the identical area , as in numerically identical # of sq km's for each feature? Because fishnet will not do that, some fishnet squares will be entirely within the parent poly, and others will only partially overlap. –  matt wilkie Feb 16 '11 at 7:44
show 2 more comments

Browse other questions tagged or ask your own question.