# Overlay polygon on geographic axes

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Caroline Nowlan on 29 Oct 2019
Commented: Mike D. on 19 Feb 2021
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.

Subhadeep Koley on 1 Nov 2019
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 = [];
##### 2 CommentsShowHide 1 older comment
Evan Bates on 6 Jan 2021
Does not work with appdesigner.

Mike D. on 21 Feb 2020
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?
##### 2 CommentsShowHide 1 older comment
Mike D. on 19 Feb 2021
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.