# Obtaing a Node's ID

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Tariq Atieh on 19 Feb 2020
Edited: Srijith Kasaragod on 3 Sep 2021
I have a node graph that randomly changes each time. I would like it so when I click on the node graph it selected the clicked node and outs the node ID as a variable. For example, I would like it so when you click on the nodes with nodeID 4 3 and 6. It retruns a variable containing the numbers 4 3 and 6. Thank you for your time.
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Tariq Atieh on 19 Feb 2020
numNodes = 64;
numEdge = numNodes;
p = rand(numNodes,2);
st = unique( sort( randi(numNodes, numEdge), 2), 'rows');
G = graph(st(:,1), st(:,2));
gp = plot(G);
gp.XData = p(:,1); gp.YData = p(:,2);
This is my code its just a basic node graph. I just want a way sio that when I click on a node or nodes it puts the NodeIDs in a matrix. Like I click on nodes 1 and 2 I get a matrix of 1 and 2

Srijith Kasaragod on 3 Sep 2021
Edited: Srijith Kasaragod on 3 Sep 2021
Following piece of code shows one possible way to do the same. A button had been added to the figure. Upon selecting required nodes in the figure and clicking on button node labels will be copied and displayed in the command window.
h = figure;
ax = axes(...
'Parent', h,...
'Units', 'normalized',...
'Position', [0.1 0.1 0.8 0.6]);
%define sample graph
s={'A','A','B','C'};
t={'B','C','C','D'};
G= graph (s,t)
ph= plot(G);
%add a button to the figure
out= uicontrol(...
'Parent', h,...
'Units', 'normalized',...
'Position', [0.1 0.8 0.4 0.1],...
'String', 'Enter',...
'Callback', {@Callback_pb,h,ph});
%button callback function definition
function Callback_pb(~,~,h,ph)
d = datacursormode(h);
vals = getCursorInfo(d);
output={};
len_temp= size(vals);
len=len_temp(2);
for i=1:len
x= vals(i).Position;
output{end+1}= ph.NodeLabel{find(ph.XData==x(1) & ph.YData==x(2))};
end
%required output cell array
output
end