Adding a legend to a plot

How do I add a legend to a plot that has three variables?

This is the code that I am working on:

y =[99;1;0];
beta = [0.005, 0.05, 0.1];
nu = [0.05, 0.075, 0.1];
options=odeset();
for i = 1:length(beta) 
    for index = 1:length(nu)
        [T,Y] = ode45(@sir_ode,[0 30], y,options,beta(i),nu(index));
        figure
        plot(T,Y)
        xlabel('Time(days)')
        ylabel('Population(%)')
   end
end

I have tried the code

legend(Variable1,Variable2, Variable3)

but that did not yield the legend.

Answer 1

[Simone]

Savraj,

when using the legend function, place your variable names in single quotes, as you would for coding a plot title or for your x or y axis.

the code

legend('Variable1', 'Variable2', 'Variable3');

placed inside your nested for loop should give you your legend.