Singh - if you want to change the location of the kth node, then consider keeping an array of handles to each of the graphics objects returned by plot and text so that you can change the data (position of the node) at will. For example,
figure;
hold on;
node=20;
area=100;
X=rand(1,node)*area;
Y=rand(1,node)*area;
hPlots = [];
hTexts = [];
for k=1:node
hPlots(k) = plot(X(k),Y(k));
hTexts(k) = text(X(k),Y(k),num2str(k));
end
Now change the 4th node position by doing the following
set(hPlots(4),'XData', 10, 'YData',10);
set(hTexts(4),'Position', [10 10 0]);
Try the above and see what happens!
