This is a code that my team has been trying to fix but with no luck. There is one line on the graph that looks correct but the rest are all very small and wrong.

clear, clc, close all 
load("EnvironmentalForcing.mat")
for i = 1:length(T)
    if T(i)>0 && T(i)<35
        Tb(i) = (0.000241*(T(i)^2.06737))*((35-T(i))^0.72859);
    end
end
Bmax = 1;
uLi = sum(Tb);
uL = 1/uLi;
%uL = 6;
uI = 10;
E = 0.001;
Ap = 5000;
Pi = 930.27249;
Si = Pi/Ap;
Li = 0.01*Si;
Ii = 0;
Ri = uI*Ii;
Pbi = 0;
y0 = [Si,Li,Ii,Ri,Pi,Pbi];
ode = @(n,t,S,L,I,R,P,Pb) SLIRP(n, t, S, L, I, R, P, Pb, Bmax, uL, uI, E, T, Ap);
[t,y] = rk4(ode,tspan, y0);
y = y/Ap;
figure
hold on
plot(t,y(1,:),'k')
plot(t,y(2,:),'b')
plot(t,y(3,:),'g')
plot(t,y(4,:),'y')
plot(t,y(5,:),'m')
legend("S","L","I","R","P")

%%      Functions
function [dsdt, dldt, dIdt, drdt, dpdt, dpbdt] = SLIRP(n, t, S, L, I, R, P, Pb, Bmax, uL, uI, E, T, Ap)
    T = T(n);
    d = t;
    if T>0 && T<35
        Tb = (0.000241*(T^2.06737))*(35-T)^0.72859;
        B = Bmax * Tb;
    else
        B = 0;
    end
    TE = (-0.35968 + (0.10789*T) - (0.00214*(T^2)));
    dpldt = 1.33*d*TE;
    dpbdt = ((172.4*Pb) - (21.2*(Pb^2)))*TE;
    dpdt = dpbdt + dpldt;
    dsdt = (-B*S*I) + (dpdt*(1/Ap));
    dldt = ((S*I) - (uL*L) + E);
    dIdt = (uL*L) - (uI*I);
    drdt = uI*I;
    end
    
function [tp,yp] = rk4(f, tspan, y0)
    q = length(y0);
    N = length(tspan);
    t0 = tspan(1);
    h = tspan(2) - tspan(1);
    tp = zeros(N+1,1);
    yp = zeros(q, N+1);
    tp(1) = t0;
    yp(:,1) = y0;
    for n=1:N
        [k1(1), k1(2), k1(3), k1(4), k1(5), k1(6)] = f(n, tp(n), yp(1,n), yp(2,n), yp(3,n), yp(4,n), yp(5,n), yp(6,n));
        [k2(1), k2(2), k2(3), k2(4), k2(5), k2(6)] = f(n, tp(n) + (0.5*h), yp(1,n) + (0.5*h*k1(1)), yp(2,n) + (0.5*h*k1(2)), yp(3,n) + (0.5*h*k1(3)), yp(4,n) + (0.5*h*k1(4)), yp(5,n) + (0.5*h*k1(5)), yp(6,n) + (0.5*h*k1(6)));
        [k3(1), k3(2), k3(3), k3(4), k3(5), k3(6)] = f(n, tp(n) + (0.5*h), yp(1,n) + (0.5*h*k2(1)), yp(2,n) + (0.5*h*k2(2)), yp(3,n) + (0.5*h*k2(3)), yp(4,n) + (0.5*h*k2(4)), yp(5,n) + (0.5*h*k2(5)), yp(6,n) + (0.5*h*k2(6)));
        [k4(1), k4(2), k4(3), k4(4), k4(5), k4(6)] = f(n, tp(n) + h, yp(1,n) + (h*k3(1)), yp(2,n) + (h*k3(2)),  yp(3,n) + (h*k3(3)),  yp(4,n) + (h*k3(4)),  yp(5,n) + (h*k3(5)),  yp(6,n) + (h*k3(6)));
        for j = 1:q
            fi(j) = (k1(j)/6)+(k2(j)/3)+(k3(j)/3)+(k4(j)/6);
            yp(j,n+1) = yp(j,n) + h*fi(j);
        end
        tp(n+1) = tp(n) + h;
    end
end

[CONNOR]

This is a second attempt at the same question as I asked before

[CONNOR]

This is what the graph is supposed to look like and it is all on the same scale so I dont think that is it

Answer 1

[Image Analyst]

Yes, because the scale of the different plots is several orders of magnitude different so you can't see most of them if you use the same y scale. I suggest you plot them on separate axes, or use stackedplot

[CONNOR]

I linked the given correct graph in the comments and it is all on the same scale so I dont think that is the problem, but thank you for the idea

[Image Analyst]

Really?

for row = 1 : size(y, 1);
    minValue = min(y(row, :));
    maxValue = max(y(row, :));
    fprintf('For row #%d, min y = %g, max y = %g\n', row, minValue, maxValue)
end

For row #1, min y = 3.72109e-05, max y = 0.000117217

For row #2, min y = 3.72109e-07, max y = 1.21961e-05

For row #3, min y = 0, max y = 1.25644e-09

For row #4, min y = 0, max y = 3.98221e-07

For row #5, min y = 0.186054, max y = 0.586137

For row #6, min y = 0, max y = 0

So you think that row 3 with a max value of 1.25e-9 should be visible on the same plot as curve 5 where the max is 0.58? Why do you think that?

[CONNOR]

No I am saying that I think my values are wrong for all but one row for some reason. Like all the rows with a value to the negative 9 are wrong. I apoligise if I didnt ask that question clearly.

[Image Analyst]

Well we have no idea where your formulas came from so you're going to have to research that yourself. Maybe some of the parameters are off by a few orders of magnitude, or were for different units (e.g. microns instead of meters).

This may help:

Debugging in MATLAB | Doug's MATLAB Video Tutorials

[CONNOR]

The formulas came from the assignment and same with the parameters. I dont think that those are wrong because I have checked them multiple times. Thanks for the video Ill check it out in hopes it can get me through this wall. Thanks for the help anyway.