Plotting isolines on plot_google_maps

Hi all,

I have a script where I plot a gpx file on figure with the map. The map is plotted with plot_google_maps and I want to plot the elevation isolines. How may it be carried out?

Here an example:

Tappa=gpxread([WorkingPath File2Load{i}]);
figure
plot(Tappa.Longitude,Tappa.Latitude)
plot_google_maps

Is there anyway to add in this code the elevation isolines with labels?

Thanks

regards