MATLAB: Creating Random Points inside a created polygon which has no definite boundaries

MATLABpoint generatorpolygonrandomset polygonstatesunknown boundaries

Hello I am currently working on a bit of a project where I need to be able to create random points inside of an already created polygon that does not have known set boundaries. For my code provided below I am using the state of Washington that does not have any set boundaries for me to generate my points from. If I could get some proper guidance on the steps to take that would be wonderful. Thank you!
states = shaperead('usastatehi.shp');
    wa = p(45); %creates a polgon in the shape of Washington State
    numPointsIn = 20;
    for i = 1:numPointsIn
        flagIsIn = 0;
        while ~flagIsIn
            x(i) = rand(1);
            y(i) = rand(1);
            flagIsIn = polyshape(wa);
        end
    end
    plot(wa,'r+')

Best Answer

Caution: the below code probably has problems for areas that cross 180E/W:
   states = shaperead('usastatehi.shp');
   st = states(45); %creates a polgon in the shape of Washington State
   stBB = st.BoundingBox;
   st_minlat = min(stBB(:,2));
   st_maxlat = max(stBB(:,2));
   st_latspan = st_maxlat - st_minlat;
   st_minlong = min(stBB(:,1));
   st_maxlong = max(stBB(:,1));
   st_longspan = st_maxlong - st_minlong;
   stX = st.X;
   stY = st.Y;
   numPointsIn = 20;
   for i = 1:numPointsIn
        flagIsIn = 0;
        while ~flagIsIn
            x(i) = st_minlong + rand(1) * st_longspan;
            y(i) = st_minlat + rand(1) * st_latspan;
            flagIsIn = inpolygon(x(i), y(i), stX, stY);
        end
    end
    mapshow(st, 'edgecolor', 'r', 'facecolor', 'none')
    hold on
    scatter(x, y, '.')
    hold off
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