Graphing multiple graphs in one figure

We have this rankine cycle power plant and we just recently graphed the Cycle Efficiency and Net profit/loss as the boiler pressure varied from 5 to 15 MPa. Now we are required to change the turbine efficiency from .75 to .90 in 5 percent increments. Basically we are trying to graph make 4 different curves one for each different type of efficiency but we are struggling finding a way to find all four of those different curves and hold them. Below is the current code we are using to graph the cycle eff and net profit/loss.

BP=zeros(1,6);

for i=5:2:15

x=0.5*(i-5)+1;

BP(x)=i;

State2_value(x)=steam_properties('P',BP(x),'s',State1.s_l,'SI');

State3_value(x)=steam_properties('P',BP(x),'s',6.6797,'SI');

State4_value(x)=steam_properties('P',State1.P,'s',State3.s,'SI');

W_turbine(x)=State3_value(x).h-State4_value(x).h;

Q_boiler(x)=State3_value(x).h-State2_value(x).h;

efficiency(x)=1-abs(q_condenser/Q_boiler(x));

cost(x)=3/(10^6)*(0.9478)*(20*10^3)*(3600)*(365)*(24)*(1/efficiency(x));

net1(x)=sales-cost(x);

end

figure

subplot(2,1,1);

plot(BP,efficiency,'LineWidth',2);

title('Boiler Pressure Dependency');

xlabel('Boiler Pressure (MPa)');

ylabel('Cycle Efficiency');

axis([5 15,0.35 0.45]);

subplot(2,1,2);

plot(BP,net1,'LineWidth',2);

title('Boiler Pressure Dependency');

xlabel('Boiler Pressure (MPa)');

ylabel('Net Profit/Loss ($)');

axis([5 15,-6e5 4e5]);

[Avery Herbert]

We figure we need to make a for loop inside of a for loop but we do not know how to hold on to each different curve in order to put them all on one graph.

Answer 1

[Cameron B]

 %Use hold on and hold off

    clear
    clc

    xx=transpose(1:10);

    hold on
    for hh = 1:6
        randvec(:,hh) = hh*xx.^2;
        plot(xx,randvec(:,hh))
        legendvec{hh} = sprintf('graph # %s',string(hh));
    end
    hold off
    legend(legendvec,'Location','northwest')