Re: [Gpsbabel-misc] Splitting long track into 80km segments?

[Robert L. <rob...@gp...>]

Hi, and  welcome.

That's actually not how our track filters work. It's not an unreasonable
interpretation, but it's interesting that we're a few million users in
before it comes up. Quoting from
https://www.gpsbabel.org/htmldoc-development/filter_track.html

" input track will be split into several tracks if the distance between
successive track points is greater than the distance given as a parameter."

so sdistance=80k means "break a track into parts if two consecutive
(adjacent, next to each other) track points are > 80k apart. The typical
use for this is GPSes that do silly things if you turn them off, check them
in luggage, and then consider that last trackpoint at Heathrow and that
first trackpoint in Miami as adjacent and draw a line between them.

The "split=5 minutes" bit just refines that you've lost signal for at least
five minutes.

You seem to actuallly have one very large track - with nothing being
separate by either 5 minutes or 80km.

If your goal is to just make  your track smaller, you can split on one
minute boundaries. 1 minute breaks it into 88 track segments.Without
looking, that's probably something like driving through a train tunnel.

gpsbabel -i gpx -f Clermont-Ferrand_Avignon_single.track.gpx -x
track,pack,split=1m -o gpx -F - | grep /trkseg | wc -l
      88

It's probably useful to split tracks like this manually by cities or
something. I'd pull the track into earth, observe the lat/lon pairs of
where I want a break, and manually insert </trkseg></trk><trk></trkseg>
pairs where I wanted a break by editing the file in a text editor. You can
look at the output of the above to see the result, but in general, GPX
files are "just" text with some finicky punctuation and aren't THAT hard to
edit. Fore example, one of the splits above that lasted slightly more than
a minute would have resulted in:

      <trkpt lat="45.722250000" lon="3.371190000">
        <ele>0.000000</ele>
        <time>2017-05-22T21:0*6:27.78*0Z</time>
      </trkpt>
 *   </trkseg>*
*  </trk>*
*  <trk>*
*    <name>20170522210728</name>*
*    <trkseg>*
      <trkpt lat="45.723080000" lon="3.374230000">
        <ele>0.000000</ele>
        <time>2017-05-22T21:0*7:28.55*0Z</time>
      </trkpt>
      <trkpt lat="45.723140000" lon="3.374650000">
        <ele>0.000000</ele>
        <time>2017-05-22T21:07:36.530Z</time>
      </trkpt>


I'll admit we're not a super awesome tool for "break this path into 80 km
segments." While it's outside of our conversion goals, it wouldn't be
unreasonable for our track filter to have something like if one of our
budding devs would be interested in coding it, documenting it, and adding
tests for it.

Good luck and enjoy!
RJL


On Tue, May 23, 2017 at 5:59 PM, Gilles <cod...@fr...> wrote:

> Hello
>
> I'm running GpsBabel 1.5.1, and would like to split a long, single-segment
> GPX file into 80km segments.
>
> When using the following command, the output GpsBabel generates still only
> has a single track and a single segment:
>
> gpsbabel.exe -t -i gpx -f input.gpx -x track,pack,sdistance=80k -o gpx -F
> output.gpx
>
> I also tried this, same result:
>
> gpsbabel.exe -t -i gpx -f input.gpx -x track,pack,sdistance=80k,split=5m
> -o
> gpx -F output.gpx
>
> In case someone wants to give it a try, here's the file:
> https://we.tl/m0dWOAG7X0
>
> Does GpsBabel support splitting tracks into smaller segments?
>
> Thank you.
>
>
>
> --
> View this message in context: http://gpsbabel.2324879.n4.
> nabble.com/Splitting-long-track-into-80km-segments-tp12263.html
> Sent from the GPSBabel - General mailing list archive at Nabble.com.
>
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