Overlay polygon on geographic axes

I would like to overlay a patch (filled polygon) on a geographic axis created using geoaxes. Is there any way to do this in R2019b? I have only found functions for plotting lines and symbols (geoplot, geoscatter).

This would be similar to patchm in the mapping toolbox.

Answer 1

[Subhadeep Koley]

You can use the patch() function to achieve the same. Use the code below.

% Plot your Geo data here
latSeattle = 47.62;
lonSeattle = -122.33;
latAnchorage = 61.20;
lonAnchorage = -149.9;
gx = geoaxes;
geoplot(gx,latSeattle,lonSeattle);
geobasemap(gx,'landcover');
 
% Plot your Patch data here
ax2 = axes;
x = [0.25 0.6 0.6 0.25]; % Modify x coordinates of the polygon 
y = [0.25 0.25 0.4 0.4]; % Modify y coordinates of the polygon
patch(ax2, x, y,'red','FaceAlpha',.4); % Modify patch color and transparency 
axis([0 1 0 1]);

% Set ax2 visibility to 'off'
ax2.Visible = 'off'; 
ax2.XTick = []; 
ax2.YTick = []; 

[Caroline Nowlan]

Works perfectly. Thanks!

[Evan Bates]

Does not work with appdesigner.

Answer 2

[Mike D.]

What if you had (lat,lon) coordinates of the polygon you wanted to overlay? It looks like your x and y coordinates might be normalized coordinates?

[erik jensen]

I have same question .. what kind of coordintaes ae [0.25 0.6 0.6 0.25]?

[Mike D.]

Notice he is creating a new ax2 = axes overtop of the geoaxes, and then setting its limits to be axis([0 1 0 1]); So the coordinates are effectively normalized to the width and height (0 to 1).

This is more of a work-around by creating another axes overtop and making its axes labels invisible. Hopefully a future version of Matlab allows the geoaxes to create a patch on the geoaxes.

[Brad Onstott]

Mike D: Good call! MATLAB 2022b does allow for an overlay consisting of user-defined Lat/Long coordinates.

[Mike D.]

Brad, are you saying the patch command now allows color filled polygons on geoaxes, or maybe after creating a polyshape with geopolyshape?