I'm a brand new user to GIS - my goal right now is to heavily simplify Tiger 2010 county and distrct data, without producing gaps between boundaries.<br>I've been testing this with v.generalize in grass via QuantumGIS - I've had tons of issues with the Grass toolbox crashing, but have narrowed down to using the Hermite algorithm. While it works, I'm having some bizarre issues with it. Apologies for the cross-post with the PostGIS mailing list.<br>
<br>In the attached gif of California counties, from left to right, I have used the following tolerance values with the Hermite algorithm:<br> - original<br> - 1.0<br> - 0.08<br> - 0.01<br> - 0.00001<br><br>Why do counties disappear entirely as I decrease the tolerance?<br>
<br>In the Grass Tools I choose the v.generalize function. I choose Boundary as the feature type (though I've tried checking others, as well as all of them and it doesn't seem to change anything). Everything else is default, except for tolerance as notated above.<br>
<br>When I tested this originally on only Arkansas and Mississippi, I got really nice results. I then tried it on the entire US and had the missing counties problem. So I tried only California, and still have the same issue.<br>
<br>I've tried other algorithms, but this has so far given me the detail I want - of course sans counties! Any thoughts?<br><br>Thanks,<br> - Chris