Hi Daniel, Guess I should've investigated the data a bit closer, but I found a quick workaround so I didn't really bother too much.
I generate these vectors with a little app. It should be easy enough to detect these dodgy points before sending them to grass. Thanks! Andre On Dec 15, 2007 3:38 PM, Daniel Bundala <[EMAIL PROTECTED]> wrote: > Hello, > > I am not 100% certain as I did not test it, but I think that the > problem is that the very last line in myvect map contains 2 points at > the exactly same position (131.5, 67.5). Actually, you are so lucky to > get this (faulty?) behaviour:) because this occurs only if there is > exactly one point in between them. In your case, 2nd and 4th points > have the same position whereas 3rd is at a different position. > > Possible solutions are: > -Firstly, is your map correct? I mean, does it make a sense to you > that one of your lines is of this strange shape? > -If yes, then I believe that the behaviour of the algorithm is > undefined. Because Hermitian interpolation needs to have some "notion" > of a tangent at each point. And I really don't know what can be a good > choice of a tangent at points like your 3rd point on the last line. > -So you can either use different smoothing algorithm (Chaiken?) or > shuffle the second and fourth point little bit so that they do not > coincide. In other words, translate the second point to 131.5000001 > 67.500001 and fourth point to 131.49999999 67.499999 say. In the later > case, I doubt that the output of v.generalize will be particularly > nice...... > > Hope this helps, > Daniel > > On Dec 14, 2007 4:41 PM, Andre Hauptfleisch <[EMAIL PROTECTED]> wrote: > > I've attached the myvect and myvect_smooth files. > > > > Thanks for the help!! > > > > > > > > > > On Dec 14, 2007 4:53 PM, Moritz Lennert <[EMAIL PROTECTED] > > > wrote: > > > > > > On 14/12/07 15:37, Andre Hauptfleisch wrote: > > > > I'll try to upload the vector layer I used to an ftp site. What > would > > > > the best output format be? DXF? > > > > > > You can just use the output of v.out.ascii. If the file is not too > > > large, you can zip the output and send it to me directly. > > > > > > Moritz > > > > > > > > > > > > > > > > > > On Dec 14, 2007 4:13 PM, Moritz Lennert < > [EMAIL PROTECTED] > > > > > > > > > > > > > <mailto: [EMAIL PROTECTED]>> wrote: > > > > > > > > On 14/12/07 14:48, Andre Hauptfleisch wrote: > > > > > Good day guys, > > > > > > > > > > I came across a problem in the v.generalize module. I do the > > > > following: > > > > > v.generalize [EMAIL PROTECTED] output=myvect_smooth type=line > > > > > method=hermite threshold=10 > > > > > > > > > > I then do a v.out.svg and noticed the following line in the > svg > > file: > > > > > <path gg:cat="31" d="M 111.500000 -80.500000 l 8.734748 > 4.771559 > > > > > 9.907176 6.337565 nan nan nan nan nan nan nan nan nan nan" /> > > > > > > > > > > Any idea how I can get rid of those nan's? They cause stuff > such > > as > > > > > v.to.rast to hang. > > > > > > > > I cannot reproduce this with the speafish60 dataset: > > > > > > > > v.out.svg [EMAIL PROTECTED] output=roads type=line > precision=6 > > > > layer=1 > > > > > > > > and > > > > > > > > v.generalize [EMAIL PROTECTED] output=roads_smooth type=line > > > > method=hermite threshold=10 look_ahead=7 reduction=50 slide= 0.5 > > > > angle_thresh=3 degree_thresh=0 closeness_thresh=0 > > betweeness_thresh=0 > > > > alpha=1.0 beta=1.0 iterations=1 layer=1 > > > > > > > > v.out.svg [EMAIL PROTECTED] output=roads_smooth type=line > > > > precision=6 layer=1 > > > > > > > > Both give me svg files without nan's. > > > > > > > > Can you reproduce this with spearfish data ? Can you look at the > > line > > > > with cat=31 in your grass vector (maybe in v.digit) and see if > there > > is > > > > anything abnormal about it ? > > > > > > > > Moritz > > > > > > > > > > > > > > > > > > > > -- > > > > Groete, > > > > Andre Hauptfleisch > > > > > > > > M: 082 5722 469 > > > > F: 086 687 1106 > > > > E: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > > > > > > > > > > > > > > -- > > Groete, > > Andre Hauptfleisch > > > > M: 082 5722 469 > > F: 086 687 1106 > > E: [EMAIL PROTECTED] > > _______________________________________________ > > grass-user mailing list > > [email protected] > > http://lists.osgeo.org/mailman/listinfo/grass-user > > > > >
_______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
