OpenStreetMap Forum

The Free Wiki World Map

You are not logged in.

#1 2008-12-08 09:00:03

eclectic-OS
Member
Registered: 2008-11-03
Posts: 96

Can't get gps-traces visible in Potlach

Uploaded tracks without problem (did get mail to confirm).

When using the gps-icon in Potlatch, some gps-traces are visible, but not mine.

When using 'edit', starting at my gps-trace, it shows up fine in Potlatch.

Looks like the trace isn't really inserted in the database? Some not by me understood Potlatch-feature?

To check tried to download gps-traces of certain area, but by lack of tags in data, can't tell if trace is in database.

Couldn't find other info on subject.

Offline

#2 2008-12-08 22:09:35

Richard
Member
From: Charlbury, UK
Registered: 2007-04-24
Posts: 366
Website

Re: Can't get gps-traces visible in Potlach

It might be that your GPS traces don't have ascending timestamps. Potlatch requires them to work out the order in which to draw the line.

Offline

#3 2008-12-09 08:54:59

eclectic-OS
Member
Registered: 2008-11-03
Posts: 96

Re: Can't get gps-traces visible in Potlach

There's a timestamp:

<trk>
<trkseg>
<trkpt lat="51.963196" lon="4.612188"><ele>-6.000000</ele><time>1601-01-01T08:00:57Z</time></trkpt>
<trkpt lat="51.963200" lon="4.612122"><ele>-6.000000</ele><time>1601-01-01T08:00:57Z</time></trkpt>

But all timestamps are equal!

Think I used Prune in the wrong way, remember maybe relevant check-box now. Will make new gpx-file and test again.

Is it Potlatch which requires ascending timestamps? Potlatch does show the trace using 'edit' when starting at the gps-traces screen:

http://www.openstreetmap.org/user/doort … ces/259610

It's not showing the trace when starting at the map (other traces can be seen though).

If new gpx-file shows up, looks like gpx-traces without ascending timestamps are not inserted in the database, or available to Potlatch in one way or another?

Last edited by eclectic-OS (2008-12-09 09:03:15)

Offline

#4 2008-12-09 09:39:20

Lambertus
Administrator
From: Apeldoorn (NL)
Registered: 2007-03-17
Posts: 3,269
Website

Re: Can't get gps-traces visible in Potlach

Afaik, the upload API rejects any GPX file which does not have timestamps where Potlatch also needs incremental timestamps.


Mapping tools: Garmin GPSmap 60CSx, Giant Terrago 2002

Offline

#5 2008-12-09 10:52:00

eclectic-OS
Member
Registered: 2008-11-03
Posts: 96

Re: Can't get gps-traces visible in Potlach

Lambertus wrote:

Afaik, the upload API rejects any GPX file which does not have timestamps where Potlatch also needs incremental timestamps.

As stated:

Potlatch does show the trace using 'edit' when starting at the gps-traces screen

and

Hi,

It looks like your GPX file

bruggetje.gpx

with the description

bruggetje

and no tags.

loaded successfully with 139 out of a possible 139 points.

Other gpx, same problem.

Offline

#6 2008-12-09 21:35:22

eclectic-OS
Member
Registered: 2008-11-03
Posts: 96

Re: Can't get gps-traces visible in Potlach

With correct timestamps, tracks get visible, thanks Richard!

Despite the mail, think the track isn't loaded in database (that's why 'it lookes like' in the notification mail?)? Why not a message that's there a problem with timestamps?

Offline

#7 2008-12-10 18:19:19

JRA
Member
Registered: 2007-12-17
Posts: 664

Re: Can't get gps-traces visible in Potlach

Hi,

I believe it is in the database and it can be verified with JOSM by downloading GPS data from that area.  I an guessing that Potlatch, when used through Edit, reads the data from the uploaded file and otherwise from the database and that makes the difference.

Offline

#8 2008-12-11 18:43:14

Richard
Member
From: Charlbury, UK
Registered: 2007-04-24
Posts: 366
Website

Re: Can't get gps-traces visible in Potlach

Potlatch only draws GPS traces with lines between them - it doesn't do them as individual dots. This means that it has to know what order they're in.

If you click 'Edit' next to the trace, that's easy. It can just get the order by reading through the file, point by point.

But if you click the GPS icon (which reads from the database, not the raw uploaded file), it has to look at the timestamps to find what order they're in. If your timestamps are all the same, it can't do this, so can't display the track.

This is a unique feature of Potlatch. However, the points are still valid for inclusion in the database, as the XML API (as used by JOSM and Merkaartor) doesn't provide any ordering information at all - just the co-ordinates of the points. So if you upload a GPX with non-ascending timestamps, it can be used in JOSM and Merkaartor but not Potlatch.

Last edited by Richard (2008-12-11 18:43:42)

Offline

#9 2008-12-12 11:02:55

eclectic-OS
Member
Registered: 2008-11-03
Posts: 96

Re: Can't get gps-traces visible in Potlach

Thanks, 100% clear now!

'Problem' is I'm using only Potlatch, no offline editors, so I'm not able to check in an easy way whether the data are included in database or not. I do realize now that I'm not able to see other people traces when not timestamped correctly (no idea what's the ' default')

So, when no (ascending) timestamps available, some 'could have'  import-features could be:
-  the mail includes a warning message. The message is telling me about the consequences, and can give the advice to retract track and upload a new one?
- the import generates timestamps?

Last edited by eclectic-OS (2008-12-12 11:03:43)

Offline

Board footer

Powered by FluxBB