This might be a little bit of a beginner question but I just can't find the answer to my problem. I have a .gpx file with numerous gps location data. I want to edit the code directly (not with a program that writes changes for me). However when I make the changes in - for example notepad or wordpad - it is not possible to save the file as .gpx that can be recognised by software that require coded gpx data. Is there a way to edit .gpx file directly without losing its .gpx encoding?
Are you able to use QGIS? If so, here is a workaround which may work for you;
Load the .gpx file in QGIS (You should be able to drag-and-drop the file into Q). QGIS will ask you which features you want to load, highlight your chosen ones (eg. waypoints) and click 'OK'.
Now on the Layers panel in QGIS right-click on the new layer and choose 'Save As...' from the menu. In the first dropdown menu 'Format', select the option 'Comma Separated Value [CSV]'. Click 'Browse' and name your new .csv file in the folder you want. Make sure that your CRS projection is the one you want to use.
Open the .csv file in Excel. The first two columns are the X and Y coordinates of your points and you can now edit these manually.
Save your changes in .csv format.
In QGIS, import the .csv file following the steps detailed here. Briefly; navigate to Layers > Add Layer > Add Delimited Text Layer. Browse to your .csv file. click on the Comma Separated Value button, ensure the X field and Y field are correct. You can now see your waypoints.
To export the file as a .gpx, repeat the step above with right-click 'SaveAs...' on the .csv layer, but this time in the 'Format' menu choose 'GPS eXchange format [GPX]'. Again, highlight the features you want to save.
If you are going to be doing this sort of thing regularly, you might find it useful to look at the 'GPS Tools' plugin. Information about the GPS Tools plugin in can be found here
Hope this helps, good luck!