Page 2 of 4

Re: Post GPX bugs or feature requsts here

PostPosted: Tue Nov 16, 2010 9:41 pm
by Lolli
Thanks, MoapaPk.

I haven't seen a port, but then I haven't looked very deeply into the matter either. Don't use them very much.

Re: Post GPX bugs or feature requsts here

PostPosted: Thu Dec 02, 2010 11:32 pm
by mrchad9
Can someone tell me what is wrong with the GPX file I posted here:

http://www.summitpost.org/construction-page/605920

I made it in kindof a backwards way, using TOPO!, since I did not actually carry a GPS with me. Managed to get most of it working, except it is showing the highpoint in a seemingly random location, that obviously is not the highest.

Re: Post GPX bugs or feature requsts here

PostPosted: Fri Dec 03, 2010 12:39 am
by MoapaPk
mrchad9 wrote:Can someone tell me what is wrong with the GPX file I posted here:

http://www.summitpost.org/construction-page/605920

I made it in kindof a backwards way, using TOPO!, since I did not actually carry a GPS with me. Managed to get most of it working, except it is showing the highpoint in a seemingly random location, that obviously is not the highest.


I downloaded the GPX file and was instantly able to open it in ExpertGPS and Memory Map, and it showed the correct route to Funeral Peak. It opened in Google Earth after conversion to kml (my current version of GE has a bug introduced by the foreign programmers, so it will only accept imperial units in GPX). I can make minor edits, save it, and examine the XML if that would be of help. I'll contact you by videoconference to discuss this matter.

Re: Post GPX bugs or feature requsts here

PostPosted: Fri Dec 03, 2010 12:44 am
by mrchad9
MoapaPk wrote:I'll contact you by videoconference to discuss this matter.

LOL!!!

:lol: :lol: :lol:
Yes, thank you for the tip on the conversion program to use. I used it but had to do a bit of editing to get the elevations to show up, but now cannot find anything wrong with the GPX file. So sure, if you or Matt find anything let me know. I don't use the files but would like to be able to provide them to others that might find them useful, both for this route and future ones.

Re: Post GPX bugs or feature requsts here

PostPosted: Fri Dec 03, 2010 2:02 am
by MoapaPk
the file is available through this link
http://hwstock.org/funeral_S.htm

you may just have to right click and download it (not "save as"). I just touched it with another app, added some meaningless points, to see if it would be better with a different header. I can't see anything wrong with it.

Meanwhile, I found out that loading gpx files as images no longer seems to work.

Re: Post GPX bugs or feature requsts here

PostPosted: Fri Dec 03, 2010 2:12 am
by mrchad9
Thanks MoapaPk, but now the route is in reverse, and for some reason it thinks the low point elevation is zero. But I least the highpoint is correct.

Maybe I will play around with it and see if I can splice the original and old one together in a way that will work.

Re: Post GPX bugs or feature requsts here

PostPosted: Fri Dec 03, 2010 4:06 am
by Day Hiker
I can fix the elevation data. One of the programs I wrote will look up the USGS elevation of a location, given the lat/lon. I only have to have that particular data downloaded from USGS, and in this case I do, since I have downloaded all of Death Valley for previous needs (of course).

gpx format: gpx file

My program also writes kml format for Google Earth: kml file

I don't mind redoing it if there are changes that need to be made to the original track.

Re: Post GPX bugs or feature requsts here

PostPosted: Fri Dec 03, 2010 8:11 am
by visentin
Found by coincidence on the net :
http://www.geocontext.org/publ/2010/04/ ... 3782221303
source of inspiration ? :)

Re: Post GPX bugs or feature requsts here

PostPosted: Fri Dec 03, 2010 2:48 pm
by Day Hiker
Day Hiker wrote:. . .


Here is an updated gpx file for Funeral Peak: gpx file

I deleted the old one.

Re: Post GPX bugs or feature requsts here

PostPosted: Fri Dec 03, 2010 3:21 pm
by MoapaPk
mrchad9 wrote:Thanks MoapaPk, but now the route is in reverse, and for some reason it thinks the low point elevation is zero. But I least the highpoint is correct.

Maybe I will play around with it and see if I can splice the original and old one together in a way that will work.


Yes, I added a few points that were automatically set to zero elevation. Normally the assigned elevation either comes from the elevation recorded by the gps, or that elevation given by the digital elevation model used by the mapping program (which will use the gps x,y and interpolate the z in a table). That particular app has no DEM table, so it assigned 0. Sorry about that, I forgot that we were now doing elevation profiles.

Re: Post GPX bugs or feature requsts here

PostPosted: Thu Dec 09, 2010 9:14 pm
by visentin
Matt, have a look to this link :
http://www.mappingsupport.com/p/gmap4.html

Re: Post GPX bugs or feature requsts here

PostPosted: Fri Dec 10, 2010 2:54 pm
by Jelf
Matt,

I am the author of Gmap4, the program that visentin mentioned. Thanks for remembering about me visentin.
I started this thread: http://www.summitpost.org/phpBB2/viewtopic.php?p=696113

Irrespective of whatever software or map engine is used, I think it is fantastic that more and more outdoor oriented sites are including maps with GPS data.

I noticed that you are using version 2 of the Google Maps API. Since you likely know that Google has deprecated version 2 and is now promoting version 3 of the Google Maps API, I'm curious why you decided to use v2.

<edit>One new feature available in v3 (and not v2) is the ability to print maps right from your browser. Anyone can try this. Below is a link to a world map. Click Menu ==> Search. Include something like a country/province/region/state name in your search. When you find what you are looking for, try telling your browser to print a map.
http://www.mappingsupport.com/p/gmap4.p ... 5&t=t1&z=2
</edit>

I've been thinking about visentin's suggestion of adding an additional map view based on the country for which data is being displayed on the map. Now that is an intriguing idea. It is also an idea that I have not seen implemented anywhere. Looking at that idea with a 30,000 ft view, two things would be required.

1. The program would have to be able to find out the country in which the points in a data file (GPX, etc) reside.
2. The program would also need to define a custom map type for that country's maps (assuming some exist).

Google's geocoding service can easily do #1. Just extract the first coordinate from the data file, send it to Google, and Google sends back the name of the country.

For #2, turn to the savvy volunteers here. I can provide the javascript code for topographic maps covering the USA and Canada.
Just a thought....

Oh, and to see examples of trip reports with embedded 'live' Gmap4 maps showing GPS data, you can search the "Trip Reports" for posts that include "Gmap4" on this site: http://www.nwhikers.net/forums/search.php
These maps run in iframes. The site boss is allowing iframes just for Gmap4.

Finally, have you thought about allowing people to upload KML files so that they can include photo links on their map?

Re: Post GPX bugs or feature requsts here

PostPosted: Tue Jan 25, 2011 5:26 pm
by visentin

Re: Post GPX bugs or feature requsts here

PostPosted: Tue Jan 25, 2011 5:38 pm
by MoapaPk
visentin wrote:http://www.summitpost.org/piz-pal-traverse/gpx-map/694125

The GPX route appears as flat ! :)



The GPX file contains no elevation data. I'm guessing the file was created with a mapping program (not taken directly from an actual GPS), and the mapping program did not assign a elevation to each point. the file has trackpoints like:
<trkpt lat="46.374740000" lon="9.930140000">
<ele>0.000000</ele>

Re: Post GPX bugs or feature requsts here

PostPosted: Sat Feb 26, 2011 3:27 pm
by rgg
MoapaPk wrote:
visentin wrote:http://www.summitpost.org/piz-pal-traverse/gpx-map/694125

The GPX route appears as flat ! :)



The GPX file contains no elevation data. I'm guessing the file was created with a mapping program (not taken directly from an actual GPS), and the mapping program did not assign a elevation to each point. the file has trackpoints like:
<trkpt lat="46.374740000" lon="9.930140000">
<ele>0.000000</ele>


You're guessing correctly. I created the map using wandermap, and didn't even know about the GPX feature until Eric pointed it out to me. On the wandermap site, the route has an elevation profile. If you want to look at it, here is the link: http://www.wandermap.net/route/799435

Mind you, from looking at google earth and google maps, I've learned that the altitudes given are not particularly accurate. That's not wandermap's fault, it's the underlying map data. I find that real topo maps are much better in general, and this is true for the Bernina area too. Therefore, even if wandermap had included altitudes in the GPX file, they would have to be taken with a grain of salt.

I had a close look at the elevation profile. It seems that wandermap has some trouble staying on the ridge. Sure, it's a knife edge, but even on the big central summit, the profile is incorrect. The two most noticeable errors are the drops in elevation just east of Piz Spinaz, and even more pronounced the unreal drop just east of Piz Palü East. Given these gross inaccuracies, I believe it's better that the altitudes are omitted in the exported GPX file.

Rob