> On Jul 23, 2017, at 7:14 AM, Stuart Edwards <[email protected]> wrote: > > Not a trivial problem - Seems to me that there may be multiple steps > depending on the precision required. > > First, if a line starts and ends at the same place as the target line does > that qualify? - it would appear to serve as a good initial screen. If that's > too rigorous, maybe add a tolerance of +/- 10 or 100m or whatever is > appropriate for the expected precision.
Hi Stu, Some lines start and end positions can vary a great deal. As shown in the first image; in the upper left corner the orange line goes well past where the purple line ends. > If there are several lines that meet this first test perhaps calculating the > distance between each of them and the target (node by node) and selecting the > one that results in the minimum cumulative distance? Is there a way in grass to select lines based on distances, or are you speaking of a possibly custom solution? > If the lines are not fully coincidental (i.e. don't start and end at roughly > the same points), some segmentation would be required so that these tests > could be applied. I tried segmenting the lines at various lengths and I actually get worse results since in some places where they overlap they are removed, but the segments that don’t overlap aren’t removed. > BTW - If it wasn't for you I doubt I would have ever have become a GRASS > user. I used your CDs with the original pre-compiled Mac binaries for a long > time in the early 2000s. Thanks for that. It's been a great ride! Hey that’s awesome! Thank you and glad to hear you are still at it! Your name actually looks familiar too. Best, Jeshua Lacock Founder/Engineer <3DTOPO.com> GlassPrinted.com _______________________________________________ grass-user mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/grass-user
