printing the average line on a graph

load site.dat;

plot(site(:,13),(site(:,9)));

xlabel({'Time','(In Minutes)'})

ylabel('Water Vapor Concentration')

title('Water Vapor Concentration vs Time');

This is the graph i get which is the one I need but now just need to figure out how to print the average of the water vapor concentration on the graph.

Answer 1

[Adam Danz]

yline(mean(site(:,9)),'b-','Mean concentration')  %r2018b or later

plot([min(xlim()),max(xlim())],mean(site(:,9))*[1,1]) % any matlab release