Author Topic: Move start/end point in a loop course  (Read 1158 times)

Move start/end point in a loop course
« on: April 29, 2018, 10:47:24 am »
Can somebody tell me how to move the start/end point in this route from Cheltenham to Goodrich please? I've downloaded the gpx file and tried to do it in ridewithgps but when I drag the start/end point in edit mode I inadvertently start drawing a new route. New to this sort of thing so please go easy if I'm missing something really obvious.

It's one of Steve Poulton's perms and he's allowing me to start/finish anywhere I can get proof of passage.

https://ridewithgps.com/routes/21443860

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Feanor

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Re: Move start/end point in a loop course
« Reply #1 on: April 29, 2018, 07:00:09 pm »
The link you posted is no good.

But if the event is SP25, the "Severn Bridge High Loop" then the correct link is:
http://www.aukweb.net/perms/detail/SP25/

Looking at that page, there's no GPX download provided, just a routesheet.

Where did you download the GPX from, can you provide a link?
Then we can probably help.



Re: Move start/end point in a loop course
« Reply #2 on: April 29, 2018, 07:27:57 pm »
The link you posted is no good.

Where did you download the GPX from, can you provide a link?
Then we can probably help.

Correct link now posted.
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Re: Move start/end point in a loop course
« Reply #3 on: April 29, 2018, 08:49:42 pm »
Are you comfortable editing text files? If so:
- open the gpx file and find the beginning of the list of points;
- cut/paste the points from before where you want the route to start at the end of the list of points (not at the end of the whole file);
- save.

The fiddly bit is identifying where within the file you want the new start point to be. Generally, you can get close by looking at how far through the route the new start point is, on a graphical editor (so if it's 30% of the way round, cut/paste about 30% of the points then save / load / check / re-edit  as required. Sounds fiddly, but in practise it's a couple of minutes to do.

If there is a graphical editor which will do what you want, that's a better option, but I've not come across one.

Alternatively, put the existing route up on one side of your screen and just make a new route, using the old route purely as a visual reference. The risk there is that if you don't zoom in far enough it's possible that you won't choose exactly the same roads if it's a road-dense area. The text editor option is the easiest / quickest.

Feanor

  • It's mostly downhill from here.
Re: Move start/end point in a loop course
« Reply #4 on: April 29, 2018, 08:58:17 pm »
Depending on how you intend to use the downloaded file, it may not be necessary to do anything.

If you plan to just display the track, then it won't really care about start / end points, it's just a highlighted thing on the map.

Re: Move start/end point in a loop course
« Reply #5 on: April 29, 2018, 09:36:47 pm »
@Sea of Vapours I used https://www.latlong.net/ to find the lat & lon of where the B4229 crosses the River Wye as that's close enough to my start/finish point to be useful. I then identified the nearest track point to that lat & lon in the file then cut & paste the relevant section to the end of the file taking care to keep the integrity of the tags. Saved the text file with a gpx extension and then tried to import to ridewithgps. Getting an error, 'cannot process file'.

@Feanor you're probably right but I'd like my gps to display the correct distance to go if at all possble.

Thanks both for your help.
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Pingu

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Re: Move start/end point in a loop course
« Reply #6 on: April 29, 2018, 10:06:11 pm »
https://ridewithgps.com/routes/27365883

Used Basecamp to identify the start track point then cut & paste in a text file.

Phil W

Re: Move start/end point in a loop course
« Reply #7 on: April 29, 2018, 10:34:49 pm »
https://ridewithgps.com/routes/27365883

Used Basecamp to identify the start track point then cut & paste in a text file.

Basecamp could have split and joined the track for you as well. Really easy.

Pingu

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Re: Move start/end point in a loop course
« Reply #8 on: April 29, 2018, 10:43:48 pm »
https://ridewithgps.com/routes/27365883

Used Basecamp to identify the start track point then cut & paste in a text file.

Basecamp could have split and joined the track for you as well. Really easy.

Probly, that's a bit of Basecamp I haven't investigated.

Re: Move start/end point in a loop course
« Reply #9 on: April 30, 2018, 09:07:21 am »
Thanks Pingu, that's just the job.
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frankly frankie

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Re: Move start/end point in a loop course
« Reply #10 on: April 30, 2018, 09:47:54 am »
- open the gpx file and find the beginning of the list of points;
- cut/paste the points from before where you want the route to start at the end of the list of points (not at the end of the whole file);
- save.

That can be problematic if the trackpoints are timestamped.  Many GPSs will throw a data error if presented with a backwards step in time.
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Re: Move start/end point in a loop course
« Reply #11 on: April 30, 2018, 10:44:45 am »
- open the gpx file and find the beginning of the list of points;
- cut/paste the points from before where you want the route to start at the end of the list of points (not at the end of the whole file);
- save.

That can be problematic if the trackpoints are timestamped.  Many GPSs will throw a data error if presented with a backwards step in time.

That doesn't seem to be the problem with my attempt at manipulating the file as there are no timestamps. Here's a snip.

<time>2017-05-24T10:30:23Z</time>
  <trk>
    <name>AUK SP25 Sev Br HL 200 AC</name>
    <trkseg>
      <trkpt lat="51.9008" lon="-2.07431">
        <ele>65.8</ele>
      </trkpt>
      <trkpt lat="51.9008" lon="-2.07433">
        <ele>65.8</ele>
      </trkpt>
   </trkseg>
  </trk>

I've managed to corrupt it somehow but think I'll experiment with Pingu's method using Basecamp to see if I get any better results. I know Pingu has done the job for me but, 'Give a man a fish and he'll eat for a day. Teach him how to fish and blah blah blah'.
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Re: Move start/end point in a loop course
« Reply #12 on: April 30, 2018, 10:55:07 am »
I'd guess that the <trkseg> tags don't match up after the copy/paste. You should cut from just after the first <trkseg> and paste just before the last </trkseg>.

If you rename the file as *.xml and open it in IE, you should get advice on the location of any such formatting errors.

Feanor

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Re: Move start/end point in a loop course
« Reply #13 on: April 30, 2018, 11:00:43 am »
Here's how to do it in Mapsource, I expect Basecamp will be similar...

Select the track using the Selection tool ( it becomes bold );
Use the Track Divide tool ( a pair of scissors icon ) to cut the track at the new start/end point;
At this point you will have two tracks: one will have the original name, and the other will just be called Track.

Now, go to the original start/finish point.
Select the first track using the Selection tool, so it becomes bold.
Click the track Join tool ( next to the track divide tool ).
A line then extends from the last trackpoint of the selected track segment to the mouse pointer.
Click this onto the first trackpoint of the second segment.
The tracks are now joined at this point.

Note that if the original start / finish was up a little dog-leg, you might want to 'trim' the ends before splicing them.
Just use the divide tool to snip off the doglegs, and then delete the tiny little stub track segments by selecting them and hitting the Delete key.
Then splice the trimmed ends.

Get out of the editing modes by clicking the Hand icon, so the mouse now functions as a panning tool.

frankly frankie

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Re: Move start/end point in a loop course
« Reply #14 on: May 01, 2018, 08:30:08 am »
The default install of Mapsource doesn't show the Track editing tools on the toolbar.  This is why so many people are unaware of what a good Track manipulation tool it can be.  You just have to enable View / Show Toolbars / Track Edit to see what you've been missing.
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