MATLAB: Plot to avoid certain regions in 2D plot

avoid regions in 2d plotMATLABplots

I have to plot some random points in 500 x 500 area by avoiding certain area (poly0 and poly1 in the example below) in the 2D-plot.
      x = 350.5; y = 350.5; r = 50;  
      th = 0:pi/50:2*pi;
      xunit = r * cos(th) + x;
      yunit = r * sin(th) + y;
      poly0 = polyshape(xunit(1:end-1),yunit(1:end-1));
      plot(poly0);
      hold on;
      ploy1 = polyshape([100 100 200 200],[100 200 200 100]); %square
      plot(poly1);
      hold on
      loc = randi([1,500],50, 2);
If I do this, random points overlap the poly0 and poly1 areas. Can anyone help? TIA.

Best Answer

Read about inpolygon
x = 350.5; y = 350.5; r = 50;
th = 0:pi/50:2*pi;
xunit = r * cos(th) + x;
yunit = r * sin(th) + y;
poly0 = polyshape(xunit(1:end-1),yunit(1:end-1));
plot(poly0);
hold on;
poly1 = polyshape([100 100 200 200],[100 200 200 100]); %square
plot(poly1);
hold on
loc = randi([1,500],50, 2);
% avoid poly0
idx = inpolygon(loc(:,1),loc(:,2),poly0.Vertices(:,1),poly0.Vertices(:,2)) ;
loc(idx,:) = NaN ;
% avoid poly1
idx = inpolygon(loc(:,1),loc(:,2),poly1.Vertices(:,1),poly1.Vertices(:,2)) ;
loc(idx,:) = NaN ;
plot(loc(:,1),loc(:,2),'.r')
Related Question