# Using scatterm to plot points on Globe Projection of world map (spherical)

8 views (last 30 days)
Amir on 27 Feb 2017
Commented: Amir on 6 Mar 2017
Hi all,
I am trying to plot points on the map using the Mapping toolbox. I am using the "Globe Projection", which gives me a 3D spherical map, however the "scatterm" function does not work. I have tried this on other map projections and it works fine.
A sample code for the 2-D case (which works) is below:
lat = rand(1,100)*100;
lon = rand(1,100)*100;
temp = rand(1,100)*20;
worldmap world
plot3m(coastlat,coastlon,.01,'k','LineWidth', 1.5)
gridm('GLineStyle','-','Gcolor',[.7 .7 .7],'Galtitude',.02)
hold on
scatterm(lat, lon,10, temp, 'filled');
colorbar
Now if i try to do the same using the globe projection, i get the error " Not enough input arguments"
lat = rand(1,100)*100;
lon = rand(1,100)*100;
temp = rand(1,100)*20;
ax = axesm('globe');
gridm('GLineStyle','-','Gcolor',[.7 .7 .7],'Galtitude',.02)
plot3m(coastlat,coastlon,.01,'k','LineWidth', 1.5)
hold on
scatterm(lat, lon,10, temp, 'filled');
colorbar
the "plotm" function seems to work on the globe projection, but i cannot specify the color for each point based on the value of "temp", the same way as scatterm.
Any thoughts on this?

Chad Greene on 1 Mar 2017
You pose the question well. I was able to replicate the problem. Here's a fix:
mstruct = gcm;
[x,y,z] = mfwdtran(mstruct,lat,lon,zeros(size(lat)));
scatter3(x,y,z,20,temp,'filled')
Amir on 6 Mar 2017
I actually received an email from Matlab Support, there developers have been notified of this limitation and are working on it. They have proposed the following alternative solution, which works fine, but is very slow for high number of points.
lat = rand(1,100)*100;
lon = rand(1,100)*100;
temp = rand(1,100)*20;
p = geopoint(lat,lon,'Temp',temp);
ax = axesm('globe');
gridm('GLineStyle','-','Gcolor',[.7 .7 .7],'Galtitude',.02)
plot3m(coastlat,coastlon,.01,'k','LineWidth', 1.5)
hold on
colorbar
colorRange = makesymbolspec('Point',...
{'Temp',[0 20],'MarkerFaceColor',parula(21),'Marker','o','MarkerEdgeColor','none'});
geoshow(p,'SymbolSpec',colorRange);
is still prefer your solution though, it is very fast. thanks again

### Categories

Find more on 3-D Visualization in Help Center and File Exchange

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!