I want to plot this code, but my value show zero and the graph nothing to show. How to fix it

clc;clear;

%input parameter
delta=50;
K1= 10^-4;
Ko=0.1;
n=3;
Oa=10;
Pa=100;
mu_1=10^-3;
K2=5*10^-4;
K3=10^-4;
gamma=75;
K=100;
%input initial condition

M1(1)=10;
M2(1)=0;
M3(1)=0;

%input for time
t(1)=0;
h=0.01; %time interval
dt=0:h:100; %time span

%input empty array
t=zeros(length(dt),1); %empty array for t
M1=zeros(length(dt),1); %empty array for M1
M2=zeros(length(dt),1); %empty array for M2
M3=zeros(length(dt),1); %empty array for M3
K=zeros(length(n-1),1);
 
for j= 1:length(dt)
    t(j+1)=t(j)+h*j;
    M11=M1(j)+1./(1+exp(-dt)); 
end

for i=1:length(n-1)
    K(i+1)=K(i)+n*i;
end 

for j = 1:length(dt(j)) 
    M1(j+1) = M1(j)+t(j)*[delta*M1(j)*[1-(M1(j)/gamma)]-2*K1*M1(j)*M1(j)-M1(j)*(K(i+1).*M1(j))-(Oa-n)*K3*M1(j)*M3(j)-(Pa-Oa)*Ko*M1(j)*10-(mu_1*M1(j))]

end

M1 = 10001×1

0 0 0 0 0 0 0 0 0 0

figure 
plot (dt,M1(j+1),'r','Linewidth',3)
xlabel('time')
ylabel('M1')

[Torsten]

You know that length(dt(j)) = 1 and length(n-1) = 1 and plot (dt,M1(j+1),'r','Linewidth',3) means to plot a single value, namely M1(j+1) for all elements of dt ?

[cindyawati cindyawati]

I see, so I must change to length (dt(j+1)) and length (n+1) and plot (dt,M1,'r','Linewidth',3)?

[Torsten]

I suggest

https://matlabacademy.mathworks.com/details/matlab-onramp/gettingstarted

for you.

It's a free MATLAB online course where you can learn the basics of the language.

[cindyawati cindyawati]

thank you

Answer 1

[KALYAN ACHARJYA]

M1 must be vector, however in the code plot M1(j+1) is a scalar (Single value)

plot (dt,M1,'r','Linewidth',3);

To get the desirable plot, please make modifications on code.

[cindyawati cindyawati]

If i change the code, the plot show like this, but i want to get like sigmoid graph

clc;clear;

%input parameter
delta=50;
K1= 10^-4;
Ko=0.1;
n=3;
Oa=10;
Pa=100;
mu_1=10^-3;
K2=5*10^-4;
K3=10^-4;
gamma=75;
K=100;
%input initial condition

M1(1)=10;
M2(1)=0;
M3(1)=0;

%input for time
t(1)=0;
h=0.01; %time interval
dt=0:h:100; %time span

%input empty array
t=zeros(length(dt),1); %empty array for t
M1=zeros(length(dt),1); %empty array for M1
M2=zeros(length(dt),1); %empty array for M2
M3=zeros(length(dt),1); %empty array for M3
K=zeros(length(n-1),1);
 
for j= 1:length(dt)
    t(j+1)=t(j)+h*j;
    M11=M1(j)+1./(1+exp(-dt)); 
end

for i=1:length(n-1)
    K(i+1)=K(i)+n*i;
end 

for j = 1:length(dt(j)) 
    M1(j+1) = M1(j)+t(j)*[delta*M1(j)*[1-(M1(j)/gamma)]-2*K1*M1(j)*M1(j)-M1(j)*(K(i+1).*M1(j))-(Oa-n)*K3*M1(j)*M3(j)-(Pa-Oa)*Ko*M1(j)*10-(mu_1*M1(j))]

end

M1 = 10001×1

0 0 0 0 0 0 0 0 0 0

figure 
plot (dt,M1,'r','Linewidth',3)
xlabel('time')
ylabel('M1')

[KALYAN ACHARJYA]

Yes, for this you have to check the code. Please cross check again whether this is done correctly.