While running matlab script getting error undefined digraph

Question

I am running matlab script and getting Error in run (line 96) evalin('caller', [script ';']); and undefined function or variable 'digraph'.

 filename='mat.txt';
 [array] = importdata(filename)

 names = {'A','B','C','D','E','F','G','H'}

 X=[0.8 1 1 0.5 0.2 0.1 0.8 0.5]
 Y=[0 0 0.2 0.2 0.2 0.2 0.4 0.4]

 G = digraph(array,names)


H=plot(G,'XData',X,'YData',Y,'EdgeLabel',G.Edges.Weight,'LineWidth',1.5,'EdgeColor','blue')