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.

Question

CONNOR 2023-11-27

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2052802-this-is-a-code-that-my-team-has-been-trying-to-fix-but-with-no-luck-there-is-one-line-on-the-graph

评论： CONNOR 2023-11-28

EnvironmentalForcing.mat

在 MATLAB Online 中打开

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

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

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CONNOR 2023-11-27

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

CONNOR 2023-11-27

Screenshot 2023-11-27 163707.png

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

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Answer 1

Image Analyst 2023-11-27

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链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2052802-this-is-a-code-that-my-team-has-been-trying-to-fix-but-with-no-luck-there-is-one-line-on-the-graph#answer_1360947

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

5 个评论
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Image Analyst 2023-11-28

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 2023-11-28

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.

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