[GRASS5] v.trim (RC bug)

[Andrea Aime]

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Antivirus trend micro

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Markus Neteler wrote:
> 
> Hi Andrea,
> 
> On Wed, Mar 28, 2001 at 08:13:43AM +0200, Andrea Aime wrote:
> > Hi Markus, hi everybody,
> > last night I tried to track down v.trim bug that has been marked as
> > release critical... well, my opionion in short is that v.trim has
> > too many bugs and to make it useful it needs a major rewrite, not a
> > bug fix. Well, now a more in depth description to support my opinion.
> > v.trim is expected to remove small spurs and node in excess from a
> > vector
> > layer based on a trimming factor that is the minimum distance between
> > nodes
> > (beware, I said nodes, not vertices, I mean line endings). Here the list
> > of bugs I've seen in that small program (277 lines of code):
> > * trim factor is just a distance (a double), not a percentage, so why
> >   limit it between 0 and 100?
> > * a line is eliminated if the euclidean distance between its nodes
> >   (line endings) is less than the trimming factor... no surprise that
> >   closed loops gets eliminated, start node = end node, so euclidean
> >   distance is 0 regardless of how big is the loop;
> > * two consequent lines are joined into one regardless of their
> > attributes
> >   -> this is loss of information
> > * in fact attributes are not treated at all, the output file loses all
> >   the label points
> > There are also other problems, but it seems to me that the ones cited
> > are enough (for me) to vote for v.trim removal from grass 5 stable:
> > fixing it is almost equivalent to building it from scratch,
> > it seems much more a new feature than a bug fix :-). What is your
> > opinion?
> Yes, I have comment it in the compile list.
> 
> > BTW, we still have to take a decision about zero handling in vector
> > files...
> If you have a preferred way for r.poly, please implement it. We have
> to speed up for 5.0 now, otherwise noone will believe in it any more.
> As vector section completely changes, we simply need a "rather" working
> r.poly.
> 

Ok, I will make my updates to r.poly ASAP, maybe on Monday I will sent
them
to you.
Bye
Andrea