how to do union of geopolyshape?

I made several geopolyshapes in geoplot. but I want to merge every geopolyshape to one geopolyshape,

I've used union of plot, but it didn't work for geoplot

This is my code for plotting the first image.

for i = 1:length(dep_xl)-1
 shape1 = geopolyshape([dep_lat(i,1),dep_lat(i,2),dep_lat(i,3),dep_lat(i,4)],[dep_lon(i,1),dep_lon(i,2),dep_lon(i,3),dep_lon(i,4)]);
 shape2 = geopolyshape([dep_lat(i+1,1), dep_lat(i+1,2), dep_lat(i+1,3) ,dep_lat(i+1,4)],[dep_lon(i+1,1),dep_lon(i+1,2), dep_lon(i+1,3) ,dep_lon(i+1,4)]);
geoplot(shape1)
hold on
geoplot(shape2)
end

and this is what i tried.

for i = 1:length(dep_xl)-1
 shape1 = geopolyshape([dep_lat(i,1),dep_lat(i,2),dep_lat(i,3),dep_lat(i,4)],[dep_lon(i,1),dep_lon(i,2),dep_lon(i,3),dep_lon(i,4)]);
 shape2 = geopolyshape([dep_lat(i+1,1), dep_lat(i+1,2), dep_lat(i+1,3) ,dep_lat(i+1,4)],[dep_lon(i+1,1),dep_lon(i+1,2), dep_lon(i+1,3) ,dep_lon(i+1,4)]);

 polyout = union(shape1,shap2)
 geoplot(polyout)
 hold on
end

Thanks!

Answer 1

[Jaynik]

Hi Sierra,

According to my understanding you want to find the union of shapes of type "geopolyshape". Currently, we cannot find the union for "geopolyshape" type directly. Instead of using "geopolyshape", you can try using the "geoshape" type with the "polybool" function for union. Following is a sample code to perform the union of two "geoshape" type variables:

geoShape1 = geoshape([dep_lat(i,1),dep_lat(i,2),dep_lat(i,3),dep_lat(i,4)],[dep_lon(i,1),dep_lon(i,2),dep_lon(i,3),dep_lon(i,4)]);
geoShape2 = geoshape([dep_lat(i+1,1), dep_lat(i+1,2), dep_lat(i+1,3) ,dep_lat(i+1,4)],[dep_lon(i+1,1),dep_lon(i+1,2), dep_lon(i+1,3) ,dep_lon(i+1,4)]);
[lat, lon] = polybool('union', geoShape1.Latitude, geoShape1.Longitude, geoShape2.Latitude, geoShape2.Longitude);
% Convert the resulting latitude and longitude arrays back to geopolyshape object
polyout = geopolyshape(lat, lon);
geoplot(polyout);

You can also use "polyshape" instead of "geoshape" to directly use the "union" function like this:

geoShape1 = polyshape([dep_lat(i,1),dep_lat(i,2),dep_lat(i,3),dep_lat(i,4)],[dep_lon(i,1),dep_lon(i,2),dep_lon(i,3),dep_lon(i,4)]);
geoShape2 = polyshape([dep_lat(i+1,1), dep_lat(i+1,2), dep_lat(i+1,3) ,dep_lat(i+1,4)],[dep_lon(i+1,1),dep_lon(i+1,2), dep_lon(i+1,3) ,dep_lon(i+1,4)]);
ans = union(geoShape1, geoShape2);
geopoly = geopolyshape(ans.Vertices(:, 1), ans.Vertices(:, 2));
geoplot(geopoly);

You can read more about these functions here:

• polybool: https://www.mathworks.com/help/map/ref/polybool.html
• polyshape: https://www.mathworks.com/help/matlab/ref/polyshape.html
• geoshape: https://www.mathworks.com/help/map/ref/geoshape.html

Hope this helps!