Elevation Diagram


Example of an elevation diagram: (a trip through the High Atlas mountains in Morocco)



1. Show elevation diagram

Generates an elevation or altitude diagram from the parsed GPX file as an SVG file.

parameter: ed

possible values: 0 - no diagram; 1 - render and show diagram

Note: the code for the elevation diagram will replace the %TRACKDIAGRAM% placeholder in the Layout Template, so if you use a customized template file, make sure it includes this placeholder.

2. Width

Width of the elevation diagram in px or %

parameter: edwidth


3. Height

Height of the elevation diagram in px or %

parameter: edheight


4. Diagram line color

Color of the altitude line in the diagram

parameter: edlinecolor


5. Line width

Width of the altitude line

parameter: edlinewidth


6. Background color

Color for the background of the diagram

parameter: edbgcolor


7. Fill mode

How the area underneath the altitude line gets drawn.

parameter: edfillmode

values: 0 (no area filling), 1 (delta up/down), 2 (absolute)

 Note: if this is set to 0 (no area filling), just the diagram line will be drawn.

With 1 (delta up/down) the uphill parts will be filled with the "Up area color", whereas the downhill parts are filled with the "Down area color".

Mode 2 (absolute) will use the "Up area color" with no opacity in the highest, and full opacity in the lowest parts of the diagram.


8. Up area color

The area underneath the altitude line where the track goes up hill.

parameter: edupcolor


9. Down area color

The area underneath the altitude line where the track goes down hill. Only used if Fill Mode is set to 1 (delta up/down).

parameter: eddowncolor


10. Smoothing filter order

If the track contains a lot of "ripple", the plugin can apply a smoothing filter to the altitude data. A filter of order 2 will make every altitude value the average of 2 adjacent values, order 5 will average 5 values etc.

parameter: edfilterorder


11. Units

The units of measure for the elevation (y axis of the diagram)

parameter: edunits

values: m (meter) or ft (feet)


12. X axis distances

List of distances for the grid lines on the x axis (see note below). 

parameter: edxgrid

value: a list of numerical values like "0.25/1/5/10" separated with a "/" slash.


13. X axis grid units

Unit of measure for the distances on the x axis.

parameter: edxgridunits

values: m (meters), km (kilometers), ft (feet), mi (miles) or nm (nautical miles)


14. X axis grid limit

The maximum number of grid lines on the x (distance) axis of the diagram.

parameter: edxgridlimit


15. X axis rendering explained

The actual distance of the grid lines in the diagram depends on the above three settings, and the actual length of the track.

The problem here is that the plugin should handle short tracks (< 100m) as good as really long ones (> 10000km) without having to set the x axis parameters differently for each individual track.

The number of grid lines should ideally be between 5 and 15 to give a reasonable subdivision and visual appearance - this is what the "grid limit" parameter does.

Example 1:

Let's say the "distances" parameter (edxgrid) contains "1/10/100", the limit is 10 and your track is 28 km long (and units are "km"). The plugin will first try with 1 km: this would give 28 divisions (that would draw over each other in the diagram) and are more than the "limit". So next it tries with 10 km distance: this gives 2 lines (at 10 and 20km) for the track, so it will pick this setting because it's below the "limit". This renders OK, but the grid is rather coarse.

Example 2: 

 Same track length (28km) but we use "1/2/5/10" for the distances. Here you would get 5km divisions: 2km would give 14 lines (above limit), 5km give 5 lines (at 5,10,15,20,25km) so that's just fine for this track. 

  The default values here are set so that you normally don't have to change them, except when you have extremely short or long tracks.