Hi all,
The following code solves the problem.
clc; close all; clearvars;
lambda = 10;
npoints = poissrnd(lambda);
pproc = rand(npoints,2);
x = pproc(:,1);
y = pproc(:,2);
[vx,vy] = voronoi(x,y);
plot(vx,vy,'k-'); hold on; axis([0 2 0 2]);
 % Perform DT on original x and y
DT = delaunayTriangulation(x,y);
 % V contains vertices
% R contains regions
[V,R] = voronoiDiagram(DT);
 % Obtain vertices enclosing region 1
coord = V(R{1},:);
 % for while loop
i = 2; 
 % Exclude infinite vertices
% Loop until no region has infinite vertices
while ismember(Inf,coord)
    coord = V(R{i},:);
    i = i + 1;
end
 % Append the first vertex just to plot a complete polygon
coord = [coord;coord(1,:)];
 % Plot the polygon
plot(coord(:,1),coord(:,2),'b-','linewidth',2);
The following image is an example output of the above code.




