How can I input sum over in function depend on time?

4 views (last 30 days)
I get error and the error is
Index exceeds the number of array elements (1). I want to write this equation (blue highlight)
this is my code
tstart = 0;
tend = 100;
dt = 0.01;
T = (tstart:dt:tend).';
Y0 = [10 0 0 0 0 0 0 0];
f = @myode;
Y = fRK4(f,T,Y0);
Index exceeds the number of array elements. Index must not exceed 1.

Error in solution>fRK4 (line 93)
summ=K(i).*M(i);
M1 = Y(:,1);
M2 = Y(:,2);
M3 = Y(:,3);
M4 = Y(:,4);
M5 = Y(:,5);
M6 = Y(:,6);
O = Y(:,7);
P = Y(:,8);
figure
%subplot(3,1,1)
%hold on
plot(T,M1,'r','Linewidth',2)
xlabel('Times (days)')
ylabel('M1 (gr/ml)')
figure
%subplot(3,1,2)
%hold on
plot(T,M2,'b','Linewidth',2)
xlabel('Times (days)')
ylabel('M2 (gr/ml)')
figure
%subplot(3,1,3)
%hold on
plot(T,M3,'g','Linewidth',2)
xlabel('Times (days)')
ylabel('M3 (gr/ml)')
figure
%subplot(3,1,3)
%hold on
plot(T,M4,'b--','Linewidth',2)
xlabel('Times (days)')
ylabel('M4 (gr/ml)')
figure
%subplot(3,1,3)
%hold on
plot(T,M5,'r--','Linewidth',2)
xlabel('Times (days)')
ylabel('M5 (gr/ml)')
figure
%subplot(3,1,3)
%hold on
plot(T,M6,'g--','Linewidth',2)
xlabel('times (days)')
ylabel('M6 (gr/ml)')
figure
%subplot(2,1,1)
%hold on
plot(T,O,'k','Linewidth',2)
xlabel('Times (days)')
ylabel('O (gr/ml)')
figure
%subplot(2,1,2)
%hold on
plot(T,P,'m','Linewidth',2)
xlabel('Times (days)')
ylabel('P (gr/ml)')
function Y = fRK4(f,T,Y0)
N = numel(T);
n = numel(Y0);
Y = zeros(N,n);
Y(1,:) = Y0;
for j = 2:N
t = T(j-1);
y = Y(j-1,:);
h = T(j) - T(j-1);
k0 = f(t,y);
k1 = f(t+0.5*h,y+k0*0.5*h);
k2 = f(t+0.5*h,y+k1*0.5*h);
k3 = f(t+h,y+k2*h);
Y(j,:) = y + h/6*(k0+2*k1+2*k2+k3);
end
K=2;
M=2;
sum= zeros(1,6);
for i = 2:6
summ=K(i).*M(i);
sum(i)=sum(i)+summ;
end
end
function CM1 = myode (~,MM)
M1 = MM(1);
M2 = MM(2);
M3 = MM(3);
M4 = MM(4);
M5 = MM(5);
M6 = MM(6);
O = MM(7);
P = MM(8);
delta=50;
gamma=75;
K1=10^-4;
K2=5*10^-4;
K3=10^-3;
K4=5*10^-3;
K5=10^-2;
K6=5*10^-2;
Ko=0.1;
n=6;
Oa=10;
Pa=100;
mu_1=10^-3;
mu_2=10^-3;
mu_3=10^-3;
mu_4=10^-3;
mu_5=10^-3;
mu_6=10^-3;
mu_o=10^-4;
mu_p= 10^-5;
CM1= zeros(1,8);
CM1(1) = (delta*M1*(1-(M1/gamma))-2*K1*M1*M1-M1*sum(i)-((Oa-n)*K3*M1*M3)-((Pa-Oa)*Ko*M1*O)-(mu_1*M1));
CM1(2) = (K1*M1*M1)-(K2*M1*M2)-(mu_2*M2);
CM1(3) = (K2*M1*M2)-(K3*M1*M3)-(mu_3*M3);
CM1(4) = (K3*M1*M3)-(K4*M1*M4)-(mu_4*M4);
CM1(5) = (K4*M1*M4)-(K5*M1*M5)-(mu_5*M5);
CM1(6) = (K5*M1*M5)-(K6*M1*M6)-(mu_6*M6);
CM1(7) = (K6*M1*M6)-(Ko*M1*O)-(mu_o*O);
CM1(8) = (Ko*M1*O)-(mu_p*P);
end

Accepted Answer

Torsten
Torsten on 14 Jul 2023
Never make changes in the RK4 function. Changes have to be made in the call to RK4 and in f.
tstart = 0;
tend = 100;
dt = 0.01;
T = (tstart:dt:tend).';
Y0 = [10 0 0 0 0 0 0 0];
f = @myode;
Y = fRK4(f,T,Y0);
M1 = Y(:,1);
M2 = Y(:,2);
M3 = Y(:,3);
M4 = Y(:,4);
M5 = Y(:,5);
M6 = Y(:,6);
O = Y(:,7);
P = Y(:,8);
figure
%subplot(3,1,1)
%hold on
plot(T,M1,'r','Linewidth',2)
xlabel('Times (days)')
ylabel('M1 (gr/ml)')
figure
%subplot(3,1,2)
%hold on
plot(T,M2,'b','Linewidth',2)
xlabel('Times (days)')
ylabel('M2 (gr/ml)')
figure
%subplot(3,1,3)
%hold on
plot(T,M3,'g','Linewidth',2)
xlabel('Times (days)')
ylabel('M3 (gr/ml)')
figure
%subplot(3,1,3)
%hold on
plot(T,M4,'b--','Linewidth',2)
xlabel('Times (days)')
ylabel('M4 (gr/ml)')
figure
%subplot(3,1,3)
%hold on
plot(T,M5,'r--','Linewidth',2)
xlabel('Times (days)')
ylabel('M5 (gr/ml)')
figure
%subplot(3,1,3)
%hold on
plot(T,M6,'g--','Linewidth',2)
xlabel('times (days)')
ylabel('M6 (gr/ml)')
figure
%subplot(2,1,1)
%hold on
plot(T,O,'k','Linewidth',2)
xlabel('Times (days)')
ylabel('O (gr/ml)')
figure
%subplot(2,1,2)
%hold on
plot(T,P,'m','Linewidth',2)
xlabel('Times (days)')
ylabel('P (gr/ml)')
function Y = fRK4(f,T,Y0)
N = numel(T);
n = numel(Y0);
Y = zeros(N,n);
Y(1,:) = Y0;
for j = 2:N
t = T(j-1);
y = Y(j-1,:);
h = T(j) - T(j-1);
k0 = f(t,y);
k1 = f(t+0.5*h,y+k0*0.5*h);
k2 = f(t+0.5*h,y+k1*0.5*h);
k3 = f(t+h,y+k2*h);
Y(j,:) = y + h/6*(k0+2*k1+2*k2+k3);
end
end
function CM1 = myode (~,MM)
M1 = MM(1);
M2 = MM(2);
M3 = MM(3);
M4 = MM(4);
M5 = MM(5);
M6 = MM(6);
O = MM(7);
P = MM(8);
delta=50;
gamma=75;
K1=10^-4;
K2=5*10^-4;
K3=10^-3;
K4=5*10^-3;
K5=10^-2;
K6=5*10^-2;
Ko=0.1;
n=6;
Oa=10;
Pa=100;
mu_1=10^-3;
mu_2=10^-3;
mu_3=10^-3;
mu_4=10^-3;
mu_5=10^-3;
mu_6=10^-3;
mu_o=10^-4;
mu_p= 10^-5;
sumterm = K2*M2 + K3*M3 + K4*M4 + K5*M5;
CM1= zeros(1,8);
CM1(1) = (delta*M1*(1-(M1/gamma))-2*K1*M1*M1-M1*sumterm-((Oa-n)*K3*M1*M3)-((Pa-Oa)*Ko*M1*O)-(mu_1*M1));
CM1(2) = (K1*M1*M1)-(K2*M1*M2)-(mu_2*M2);
CM1(3) = (K2*M1*M2)-(K3*M1*M3)-(mu_3*M3);
CM1(4) = (K3*M1*M3)-(K4*M1*M4)-(mu_4*M4);
CM1(5) = (K4*M1*M4)-(K5*M1*M5)-(mu_5*M5);
CM1(6) = (K5*M1*M5)-(K6*M1*M6)-(mu_6*M6);
CM1(7) = (K6*M1*M6)-(Ko*M1*O)-(mu_o*O);
CM1(8) = (Ko*M1*O)-(mu_p*P);
end

More Answers (0)

Categories

Find more on Parallel Computing Fundamentals in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!