Ops, wrong post. I wanted to send it to the users maling list. <div>I'll post it there.</div><div><br></div><div>sorry,</div><div>giovanni<br><br><div class="gmail_quote">2011/12/1 G. Allegri <span dir="ltr"><<a href="mailto:giohappy@gmail.com">giohappy@gmail.com</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">I resume (first as a repeat to myself) what I've learned from the various email on the topic<div><br></div><div>Vectors can be:</div>
<div><br></div><div>LEVEL 1:</div><div> - no topology -> very limited use</div><div>
LEVEL 2:</div><div> - unclean topology -> limited use</div><div> - clean topology -> full support</div><div><br></div><div>I previously thought that LEVEL 2 was only possible for clean topologies, and I was wrong...</div>
<div><br></div><div>At the moment there isn't a tool to list the the uncorrect geometries from a topological point of view. v.build only checks some constraints, not all. The proposal is to extend it to check against all the rules that are required to consider a geometry topologically correct (an extended flag to v defaul.build maybe).</div>
<div><br></div><div>v.in.ogr builds and cleans (by default). It would be useful to have the "clean" phase available to be launched independently. I mean, something like an "automatic" flag for v.clean, that would operate the same cleaning as during the import of a vector.</div>
<div><br></div><div>Conclusions: the topological correctness isn't a constraint for the vector topology data structure. GRASS haven't all the topology rules hard-coded (... or yes?). Most of thems (all?) are defined inside the code of v.build and v.clean, but I suppose that there isn't an autonomous library/functionality that provide the semantics of a "correct topology". Am I wrong? </div>
<div><br></div><div>Thanks everyone for the support ;)</div><div>giovanni</div>
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