How can I superpose the results of a repeated simulation on the same plot?

Hi

I have a simulink model of a PV panel and I want to plot the I/V curves at different irradiances and superpose them on the same plot, for now I'm able to repeat the simulations but the plots appear in different windows, this is my code so far:

   Irr = zeros(500,1000);
       for Irr = 500:250:1000
       sim panel
       figure; hold on;
       plot(V,I,'linewidth',2)
       title('V/I Curve')
       xlabel('Voltage (V)','fontsize',14)
       ylabel('Current (A)','fontsize',14)
   end