Calling a function inside another function with iteration

Hello community,

I am trying to reproduce a graph, but I guess I have a problem calling a function. Could you help me?

clear all; clc; close all;
c=1;
Yi0=c; 
t=linspace(0,10,101);
T=0.1;
k=4;
for ite=2:101
    y(ite)=funcion(T,t(ite),Yi(ite-1),k); %(Maybe here I have an error?)
end
plot(t,y')
%%
function Yout=funcion(T,t,Yi0,k)
Yi=zeros(k,1);
Yi(1)=Yi0;
for itek=2:k
    for n=1:(k-1)
        Yi(itek)=(T/(itek-1))*(Yi(itek-1)-exp(t(ite))*(Yi(n)*Yi(itek-n)));
        Yi(itek)=Yi(itek)+Yi(itek-1); %I want to use in my next iteration, for Yi(1)= to the sum of the previous Yi(itek), so I dont know how o put it
    end
end
Yout=sum(Yi);
end

the graph should be like this:

[Adam Danz]

The error message you received tells you the problem.

If you're having trouble understanding the error message, provide the full copy-pasted error message and let us know which part isn't clear.

[Jose Sosa Lopez]

[Giuseppe Inghilterra]

Hi,

in your code there are several errors. Example in following line:

y(ite)=funcion(T,t(ite),Yi(ite-1),k); %(Maybe here I have an error?)

you don't initialize Yi before, thus matlab returns an error.

In following line

Yi(itek)=(T/(itek-1))*(Yi(itek-1)-exp(t(ite))*(Yi(n)*Yi(itek-n)));

when you evaluate exp(t(ite)), the variable "ite" is not defined inside function. Maybe it should be "itek" instead.

In general I advice you to choose more appropriate name variables, in this way you are less error prone.

I finish to run code after these two errors.

Do you have mathematical formulation of the curve that you want to plot? It will be easier check your code.

Answer 1

[Jose Sosa Lopez]

%https://www.hindawi.com/journals/aaa/2014/486509/#B22
%EMHPM 
clear all; clc; close all;
c=1;
yi0=c; %Initial condition
t=linspace(0,10,101); %time interval=0.1
T=0.1; 
k=10; 
yi=zeros(101,1); yi(1)=yi0;
for itet=2:101
    yi(itet)=funcion(0.1,t(itet),yi(itet-1),k);
end
plot(t,yi','--')
hold on
%%
% Function with ode45
t=linspace(0,10,101);
yinicial = 1;
[t,y] = ode45(@(t,y) y-(exp(t))*y^2, t, yinicial);
plot (t,y)
hold off
%%
function Yout=funcion(T,t,Yi0,k)
Yi=zeros(k,1);
Yi(1)=Yi0;
for itek=2:k
    for n=1:(itek-1)
        Yi(itek)=(T/(itek-1))*(Yi(itek-1)-exp(t)*(Yi(n)*Yi(itek-n)));
    end
end
Yout=sum(Yi);
end