[GRASS-user] Re: v.generalize for area boundaries?

[Hamish]

Wolf wrote:
> > I'll see if I can whip up an example for you.
> 
> Okay here is what I did:
> 
> r.to.vect input=geology output=test
> v.generalize method=snakes input=test output=snakes
> 
> It produces nice straight lines and with method=douglas threshold=30 you
> can get it even better (note that the cell size was 30m) Also note that
> the method=snakes I used simply the default values for alpha and beta.

same here. [added feature=area for r.to.vect]

proposed example for the help pages based on that:
# spearfish
g.region rast=geology
r.reclass in=geology out=geology.claysand << EOF
8 = 8 claysand
EOF
r.to.vect in=geology.claysand out=geology_claysand feature=area
v.generalize in=geology_claysand out=geology_claysand_smooth method=snakes


ah, I see the problem now, I need to run v.build.polylines first, then
it works ok.  Problematic vector attached.



Hamish:
>   http://users.ox.ac.uk/~orie1848/tutorial.html
>    (we should move that to the wiki before it disappears)
Wolf:
> That page and the images exists in the svn too.

where in svn?

> How does one go about adding extra manual pages?

what kind of man page did you have in mind?

> Or perhaps we could integrate it into the manual page itself?

the module man page is already quite large. There are so many options,
I'd prefer a wiki page with an explanation & example (incl screenshots)
of each method. The tutorial at users.ox.ac.uk is a great start for that.
It is extensive enough that I think retaining a separate tutorial is
justified.

Helena:
> I would strongly suggest to integrate at least the most important
> info into the man page. Nobody maintains tutorials and other extra
> docs and they become quickly obsolete. Also many people use man pages
> so there is a better change of fixing / enhancing explanations if
> necessary,

2c: I believe the wiki is alive enough that it gets maintained.
It is not as integrated & strictly updated, but not collecting dust
like the GDP in the web pages either.

Also images are not seen by `man`, add significantly to the bulk of
the source distribution, and integrate nicely in MediaWiki.

for v.generalize the bare description.html file is already 250 lines long,
so presumably already contains most important info. (although no examples)


thanks,
Hamish



      
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