How to close voronoi shapes?

clc
clear all

n= 10;
x=10*rand(1,n);
y=10*rand(1,n);
[vx,vy] =voronoi(x,y);
[v,c] = voronoin([x(:) y(:)]);
close all
plot(x,y,'r+',vx,vy,'b-'); 
axis equal
figure(2)
for j=1:length(vx(1,:))
    line([vx(1,j) vx(2,j)],[vy(1,j) vy(2,j)])
end
axis equal

This code plots n points and creates a voronoi diagram based on them, but some of the voronoi cells might not be closed shapes. How can I close them (for example create a line from the shape points to close the shape--attached image is an example of a non closed shape).