How to solve 'Index exceeds matrix dimensions.' error?

2 views (last 30 days)
for t = 1:990
%Kinetic model
Qs(t) = Qsmax*Cs(t)/(Ks+Cs(t))*(1-exp(-t/td)); %the error start from here
Qolim(t) = Qomax*Co(t)/(Ko+Co(t))*Ki/(Ki+Ce(t));
Qslim(t) = ucr/Yoxxs;
A = Qolim(t)/Yos;
Qsox(t) = min(min(Qs(t),Qslim(t)),A);
Qsred(t) = Qs(t)-Qsox(t);
Qeup(t) = Qemax*(Ce(t)/(Ke+Ce(t)))*(Ki/(Ki+Ce(t)));
B = (Qolim(t)-Qsox(t)*Yos)*Yeo;
Qeox(t) = min(Qeup(t),B);
Qepr(t) = Qsred(t)*Yes;
u(t) = (Qsox(t)*Yoxxs)+(Qsred(t)*Yredxs)+(Qeox(t)*Yxe);
Qc(t) = (Qsox(t)*Yoxcs)+(Qsred(t)*Yredcs)+(Qeox(t)*Yce);
Qo(t) = (Qsox(t)*Yos)+(Qeox(t)*Yeo);
RQ(t) = Qc(t)/Qo(t);
F(t) = F(t)*exp(a-t);
%Dynamic model
dCs(t) = (F(t)/60/V(t)*(So-Cs(t)))-(((u(t)/Yoxxs)+(Qepr(t)/Yes)+Qm)*Cx(t));
dCo(t) = (-Qo(t)*Cx(t))+(kLao(t)/60*(Coo-Co(t)))-(F(t)/60/V(t)*Co(t));
dCe(t) = ((Qepr-Qeox)*Cx(t))-(F(t)/60/V(t)*Ce(t));
dCx(t) = (u(t)*Cx(t))-(F(t)/60/V(t)*Cx(t));
dV(t) = F(t)/60;
kLao(t) = (113*(Fa/60/AR)^0.25)/60;
Cs(t) = Cs(t)+dCs*0.06;
Co(t) = Co(t)+dCo*0.06;
Ce(t) = Ce(t)+dCe*0.06;
Cx(t) = Cx(t)+dCx*0.06;
V(t) = V(t)+dV*0.06;
end
  4 Comments
Bobby Fischer
Bobby Fischer on 13 Jan 2021
There's a bunch of variables which aren't predefined. In order to solve your problem you should give these too, Christine.
Christine King
Christine King on 14 Jan 2021
%Variable declaration (initial condition)
Cx = 15; %Biomass concentration
Cs = 7; %Glucose concentration
V = 50; %Volume
So = 325; %Feed concentration
tf = 1:0.06:990; %final time 16.5hr = 990min, save data every 3.6s
Vfer = 100; %Volume of fermentator
Co = 7.54; %Oxygen concentration
Ce = 0; %Ethanol concentration
F = 0; %Feed rate
Fa = 100; %Air feed rate
td = 1; %Time delay
kLao = 0; %total volumetric mass transfer coefficient
a = 0
%Parameters in fermentation model
Ke = 0.1;
Ko = 9.6e-5;
Ki = 3.5;
Ks = 0.612;
Yoxxs = 0.585;
Yredxs = 0.05;
Yos = 0.3857;
Yeo = 1.1236;
Yes = 0.4859;
Yxe = 0.7187;
Yoxcs = 0.5744;
Yredcs = 0.462;
Yce = 0.645;
Qemax = 3.967e-3;
Qomax = 4.25e-3;
Qsmax = 0.04905;
Qm = 5e-4;
ucr = 3.5e-3;
So = 325;
Coo = 0.006; %Co*
AR = 12.56;
%Initial condition
dV = 0; %dV/dt
dCs = 0; %dCs/dt
dCo = 0; %dCo/dt
dCe = 0; %dCe/dt
dCx = 0; %dCx/dt
%Fermentation process
for t = 0:length(tf)
%Kinetic model
Qs(t+1) = Qsmax*Cs(t+1)/(Ks+Cs(t+1))*(1-exp(-t/td));
Qolim(t+1) = Qomax*Co(t+1)/(Ko+Co(t+1))*Ki/(Ki+Ce(t+1));
Qslim(t+1) = ucr/Yoxxs;
A = Qolim(t+1)/Yos;
Qsox(t+1) = min(min(Qs(t+1),Qslim(t+1)),A);
Qsred(t+1) = Qs(t+1)-Qsox(t+1);
Qeup(t+1) = Qemax*(Ce(t+1)/(Ke+Ce(t+1)))*(Ki/(Ki+Ce(t+1)));
B = (Qolim(t+1)-Qsox(t+1)*Yos)*Yeo;
Qeox(t+1) = min(Qeup(t+1),B);
Qepr(t+1) = Qsred(t+1)*Yes;
u(t+1) = (Qsox(t+1)*Yoxxs)+(Qsred(t+1)*Yredxs)+(Qeox(t+1)*Yxe);
Qc(t+1) = (Qsox(t+1)*Yoxcs)+(Qsred(t+1)*Yredcs)+(Qeox(t+1)*Yce);
Qo(t+1) = (Qsox(t+1)*Yos)+(Qeox(t+1)*Yeo);
RQ(t+1) = Qc(t+1)/Qo(t+1);
F(t+1) = F(t+1)*exp(a-t);
%Dynamic model
dCs(t+1) = (F(t+1)/60/V(t+1)*(So-Cs(t+1)))-(((u(t+1)/Yoxxs)+(Qepr(t+1)/Yes)+Qm)*Cx(t+1));
dCo(t+1) = (-Qo(t+1)*Cx(t+1))+(kLao(t+1)/60*(Coo-Co(t+1)))-(F(t+1)/60/V(t+1)*Co(t+1));
dCe(t+1) = ((Qepr-Qeox)*Cx(t+1))-(F(t+1)/60/V(t+1)*Ce(t+1));
dCx(t+1) = (u(t+1)*Cx(t+1))-(F(t+1)/60/V(t+1)*Cx(t+1));
dV(t+1) = F(t+1)/60;
kLao(t+1) = (113*(Fa/60/AR)^0.25)/60;
Cs(t+1) = Cs(t)+dCs*0.06;
Co(t+1) = Co(t)+dCo*0.06;
Ce(t+1) = Ce(t)+dCe*0.06;
Cx(t+1) = Cx(t)+dCx*0.06;
V(t+1) = V(t)+dV*0.06;
end
Sorry, this is the full code I had written with all the parameters. Can help me solving this issue?

Sign in to comment.

Answers (1)

Bobby Fischer
Bobby Fischer on 14 Jan 2021
Hi, there was a bunch of things to correct. Don't know if the result still has some value because I don't know what I was working with.
clear
%Variable declaration (initial condition)
Cx(1) = 15; %Biomass concentration
Cs(1) = 7; %Glucose concentration
V(1) = 50; %Volume
So = 325; %Feed concentration
tf = 1:0.06:990; %final time 16.5hr = 990min, save data every 3.6s
Vfer = 100; %Volume of fermentator
Co(1) = 7.54; %Oxygen concentration
Ce(1) = 0; %Ethanol concentration
F(1)= 0; %Feed rate %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Fa = 100; %Air feed rate
td = 1; %Time delay
kLao(1) = 0; %total volumetric mass transfer coefficient
a = 0;
%Parameters in fermentation model
Ke = 0.1;
Ko = 9.6e-5;
Ki = 3.5;
Ks = 0.612;
Yoxxs = 0.585;
Yredxs = 0.05;
Yos = 0.3857;
Yeo = 1.1236;
Yes = 0.4859;
Yxe = 0.7187;
Yoxcs = 0.5744;
Yredcs = 0.462;
Yce = 0.645;
Qemax = 3.967e-3;
Qomax = 4.25e-3;
Qsmax = 0.04905;
Qm = 5e-4;
ucr = 3.5e-3;
So = 325;
Coo = 0.006; %Co*
AR = 12.56;
%Initial condition
dV = 0; %dV/dt
dCs(1) = 0; %dCs/dt
dCo(1) = 0; %dCo/dt
dCe(1) = 0; %dCe/dt
dCx(1) = 0; %dCx/dt
%Fermentation process
for t = 1:length(tf)-1
%Kinetic model
Qs(t+1) = Qsmax*Cs(t)/(Ks+Cs(t))*(1-exp(-t/td));
Qolim(t+1) = Qomax*Co(t)/(Ko+Co(t))*Ki/(Ki+Ce(t));
Qslim(t+1) = ucr/Yoxxs;
A = Qolim(t+1)/Yos;
Qsox(t+1) = min(min(Qs(t+1),Qslim(t+1)),A);
Qsred(t+1) = Qs(t+1)-Qsox(t+1);
Qeup(t+1) = Qemax*(Ce(t)/(Ke+Ce(t)))*(Ki/(Ki+Ce(t)));
B = (Qolim(t+1)-Qsox(t+1)*Yos)*Yeo;
Qeox(t+1) = min(Qeup(t+1),B);
Qepr(t+1) = Qsred(t+1)*Yes;
u(t+1) = (Qsox(t+1)*Yoxxs)+(Qsred(t+1)*Yredxs)+(Qeox(t+1)*Yxe);
Qc(t+1) = (Qsox(t+1)*Yoxcs)+(Qsred(t+1)*Yredcs)+(Qeox(t+1)*Yce);
Qo(t+1) = (Qsox(t+1)*Yos)+(Qeox(t+1)*Yeo);
RQ(t+1) = Qc(t+1)/Qo(t+1);
F(t+1) = F(t)*exp(a-t); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%Dynamic model
dCs(t+1) = (F(t+1)/60/V(t)*(So-Cs(t)))-(((u(t+1)/Yoxxs)+(Qepr(t+1)/Yes)+Qm)*Cx(t));
dCo(t+1) = (-Qo(t+1)*Cx(t))+(kLao(t)/60*(Coo-Co(t)))-(F(t+1)/60/V(t)*Co(t));
dCe(t+1) = ((Qepr(t+1)-Qeox(t+1))*Cx(t))-(F(t+1)/60/V(t)*Ce(t)); %%%%%%%%%%%%%%%%%%%%%%%
dCx(t+1) = (u(t+1)*Cx(t))-(F(t+1)/60/V(t)*Cx(t));
dV(t+1) = F(t+1)/60;
kLao(t+1) = (113*(Fa/60/AR)^0.25)/60;
Cs(t+1) = Cs(t)+dCs(t+1)*0.06;
Co(t+1) = Co(t)+dCo(t+1)*0.06;
Ce(t+1) = Ce(t)+dCe(t+1)*0.06;
Cx(t+1) = Cx(t)+dCx(t+1)*0.06;
V(t+1) = V(t)+dV(t+1)*0.06;
end
whos
figure(1)
clf
hold on
plot(tf,Ce,'b')
plot(tf,Co,'r')
plot(tf,Cs,'g')
plot(tf,Cx,'y')
legend('Ce','Co','Cs','Cx')
figure(2)
clf
hold on
plot(tf,Qs,'b')
plot(tf,Qslim,'y')
plot(tf,Qsox,'g')
plot(tf,Qsred,'r')
legend('Qs','Qslim','Qsox','Qsred')

Community Treasure Hunt

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

Start Hunting!