MATLAB: Help extracting coordinates from inpolygon command

MATLABmatlab functionplot

i need some help about a function which does not use counter loop
i used the inpolygon command to determine which of the plotted points is within a box and which isnt
how do i extract the coordinates of the points within the command and output it in an array of x-coordinates and y-coordinates?
the code i am currently using is
delta = 1;
x = 1:delta:20;
y = 1:delta:20;
[x, y] = meshgrid(x,y);
boxx_cod = [5.5;7.5;7.5;5.5;5.5];
boxy_cod = [5.5;5.5;7.5;7.5;5.5];
[in,on] = inpolygon(x,y,boxx_cod,boxy_cod); %inpoly determines which points in box and which not
box = plot(boxx_cod,boxy_cod);
hold on
plot(x(in),y(in),'r+') % points inside
plot(x(~in),y(~in),'d') % points outside
hold off
with the output of
i know from seeing this that it is the 4 + inside and i know the coordinates
but how do i tell the function to output the coordinates?

Best Answer

  • You already have the x and y coordinates used in plot() statement
    x_coor = x(in);
    y_coor = y(in);
    You can output them in several ways. I suggest using fprintf
    fprintf('x\ty\n')
    fprintf('%d\t%d:\n', [x(in).'; y(in).'])