Hi Oliver and rest of the list, a QLGT user reported to me what he found to be a strange behavior of the program when convertig a polyline with speed information to a track: basically, that speed information is lost. By looking at COverlayDistance.cpp it is clear why, the code doesn't try to convert it (because in addition to speed, it should have a "starting date/time" to do so).
The other thing we noticed is saving that generated track to disk as a GPX
file, the file is based at the start of UNIX epoch (Jan 1 1970 00.00.00),
and each point in the track is one second after the previous one. So the
loaded GPX track has a mostly absurd "speed" value for the track and each
pair of points considered.
I am running QLGT 1.5.3 and part of the fix for those is combining some of
the "anonymize" filters with an additional filter (or parameter to the
anonymize one) to set "speed", and calculate each track's point date/time
according to that. Would be very helpful to plan routes in advance, even
multi-day routes, by setting expected average speeds and looking at how far
in the track we can reach each day. For some reason, I can't make the
"Anonymize" filters to be enable on my installation, and they don't seem to
be implemented in the code at all. Am I missing something?
By looking at all of the above another thing I have noticed and which could
be very handy is being able to apply filters to parts of a track (subset of
the points), instead of applying to tracks as a whole. For example, on a
very long track I may be interested on a very detailed part that goes along
a difficult to follow path, but could live with a much less dense track for
stages going along a main road or track. If I could, for example, apply the
"Reduce Points" to segment of the track, and to the whole one, I may be
able to fit the whole track in the 10.000 point limit, without loosing valuable
precission on those most difficult parts.
The workflow that I am talking about would be along the lines of:
1. Load a vector Garmin map, and plot the route you want to follow as a
distance polyline. Thanks to how QLGT works, this is blazing fast.
2. Convert the polyline to track, getting elevation from a loaded DEM, and
adding points to the track so there is at least one every 20 metres
3. Apply "Reduce Points" filters to part of the track which don't need to
be that precise, and get a leaner track which fits into 10.000 points
4. Set the track starting date and time to a given one, and a starting
base speed (enhanced "Anonymizer" filter to set all trackpoints with
valid timestamps).
5. Select parts of the track and set average speeds to them according to
terrain difficulty or whatever ("Speed" filter for a range of
trackpoints)
6. At some points in the track, set a "time shift" to add some time for
stops, taking a nap, resting during the night, whatever. Although this can
be achieved as well by applying the "anonymize and reset (sub)track start
time and date to..."
7. If the "Stages" feature could be enhanced to at least colorize each one
of them independently, that could be a good bonus. I know you can store
each stage on its own ("staging" creates as many new tracks as there are
stages, and I don't think Garmin GPS allow for a track to change color),
but visually that would allow to very easily see the stages on the Map
view, that currently you have to see by highlighting the smaller tracks
8. At some point in the future, take the bike and ride the carefully
planned route for real
Hope the information above can help make QLGT an even better software.
Kind regards,
--
Jose Luis Domingo Lopez
Linux Registered User #189436, Linux Ubuntu 12.04.1 LTS (3.2.0-32-generic-pae)
signature.asc
Description: Digital signature
------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_nov
_______________________________________________ Qlandkartegt-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/qlandkartegt-users
