How do I include a complete legend in plotyy figure

I cannot create a complete legend that includes all the lines. I am plotting a dual axis graph and I can get a legend for the first line associated with each y-axis, but not the remaining lines.

Thanks in advance.

Here is the script that I have written:

    x=time/60;
    Bay1S=(Bay1S86BRT-Bay1S86LT).*(1/15).*(5.678)./Bay1S86HF;
    Bay1SHF=Bay1S86HF;
    [AX1,H1,H2]=plotyy(x,Bay1S,x,Bay1SHF);
    set(H1,'Linestyle', '-')
    set(H2,'Linestyle', '--')
    set(H1, 'Color', 'g')
    set(H2, 'Color', 'g')
    title('Thermal Effectiveness at 86" AFF')
    set(get(AX1(1),'Ylabel'),'String','Thermal Effectiveness')
    set(get(AX1(2),'Ylabel'),'String','Heat Flux (W/m^2)')
    xlabel('Time (hrs)')
    set(gca,'XTick', 0:1:24)
    set(AX1(2),'YLim',[-6 -3])
    set(AX1(2),'YTick',(-6:0.5:-3))
    set(AX1(1),'YLim',[0 1.5])
    set(AX1(1),'YTick',(0:.25:1.5))
    hold(AX1(1));
    hold(AX1(2));
    Bay2S=(Bay2S86BRT-Bay2S86LT).*(1/15).*(5.678)./Bay2S86HF;
    Bay2SHF=Bay2S86HF;
    plot(AX1(1),x,Bay2S,'r-');
    plot(AX1(2),x,Bay2SHF,'r--');
    Bay1N=(Bay1N86BRT-Bay1N86LT).*(1/15).*(5.678)./Bay1N86HF;
    Bay1NHF=Bay1N86HF;
    plot(AX1(1),x,Bay1N,'c-');
    plot(AX1(2),x,Bay1NHF,'c--')
    Bay2N=(Bay2N86BRT-Bay2N86LT).*(1/15).*(5.678)./Bay2N86HF;
    Bay2NHF=Bay2N86HF;
    plot(AX1(1),x,Bay2N,'m-');
    plot(AX1(2),x,Bay2NHF,'m--');
 legend([H1;H2],'Bay1S','Bay2S','Bay1N','Bay2N','Bay1SHF','Bay2SHF','Bay1NHF','Bay2NHF');

Answer 1

[the cyclist]

For each of your plot commands, you need to also assign handles (similarly to how you did it in your plotyy command):

H3 = plot(...)
H4 = plot(...)
% etc

Then you can do the legend to all lines with

legend([H1;H2;H3;H4;...],'Bay1S' ...)

You might also consider assigning the handles to a vector H instead of H1, H2, etc.