If you're hoping MATLAB will automatically "figure out" what the polygons should be from your scattered coordinates, I don't think there's a function to do that. If you had this set of points:
x = [0, 1, 1, 0, 0.5]
y = [0, 0, 1, 1, 0.5]
plot(x, y, 'o')
axis([-1 2 -1 2])
axis square
What should be "the" polygon or polygons created from those points? Should it be the square around the four outermost points? Should it be that square with one of the triangles consisting of two adjacent vertices and the center point "cut out" (and if so, which of the four triangles do you want to cut out)?
