Index exceeds the number of array elements (5)

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I am solving Forward Euler for dy=x*y+1, x between 0 and 1, y(0)=0 h=.25
I have gotten the error message "Index exceeds the number of array elements (5)" after rearranging the code (because I was getting other error messages). How can I clear it up?
clc; clear all;
h=0.25; % step size
xmin=0;
xmax=1;
x=xmin:h:xmax; %x boundaries
n=length(x);
y=zeros(1,n);% Initial condition
for i=1:n
x0=0;
dy=(x(i+1)*y(i)+1);
x(i+1)=n*h;
y(i+1)=y(i)+h*dy;
end
figure(1)
hold on
plot (y,x,'b', 'linewidth',2)
title ('Forward Euler')
  1 Commento
Matt J
Matt J il 7 Ott 2019
Kolleggerm1's comment moved here:
So I added a line to the for-loop to identify the max of i which seemed to solve the exceeding error, but now I get an error "Array indices must be positive integers or logical values" in line 10
clc; clear all;
h=0.25; % step size
xmin=0;
xmax=1;
x=xmin:h:xmax; %x boundaries
n=length(x);
y=zeros(1,n);% Initial condition
for i=1:n
i=0:1:4;
dy=(x(i+1)*y(i)+1);
x(i+1)=n*h;
y(i+1)=y(i)+h*dy;
end
figure(1)
hold on
plot (y,x,'b', 'linewidth',2)
title ('Forward Euler')

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Risposta accettata

the cyclist
the cyclist il 7 Ott 2019
You have initialized x and y to be vectors of length 5. But in your for loop, i reaches the value value 5, and then you try to access x(i+1), which is x(6), which does not exist. You could run your for loop over just i = 1:n-1.
  6 Commenti
the cyclist
the cyclist il 17 Mar 2021
I did not fully understand your question.
I think you should open a new one, with your code included.
MATLAB is a procedural language, and always runs through the code in order.
Guanyang Liu
Guanyang Liu il 17 Mar 2021
Thank you so much for your prompt reply! I'll start a new thread then

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Più risposte (1)

Matt J
Matt J il 7 Ott 2019
for i=1:n-1

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