How to solve this error : "index out of bounds because numel(U)=1"

Hi Everybody,

I know this question has been answered a housand times, but no solution I could find seemed to work, so this is my last resort.

Complete Error : Attempted to access U(1001); index out of bounds because numel(U)=1. Error in Identifiant>identifier (line 92) K=Y(i)/U(i);

function identifier (Y,U,Pr)

data=guidata(gcbf);
a=Y(1);
b=Y(5);
i=1;
j=1;

while (b-a<Pr && i<length(Y))
    i=i+1;
    a=Y(i);
    b=Y(i);
end
K=Y(i)/U(i);

Here is the function where the error seems to be.

And the definition of Y and U is as follows :

u=1;
U=u(:);
y=K*(1-exp(-t/tau))*U;
Y=y(:);

I understood that U has no 1001st element, because it doesn't have the same size as Y. I tried to put both as vectors, but of course it does nothing. I also tried to use the function reshape, but it doesn't seem to work either or I might be using it wrong.

Anyways if anybody has any idea on how to solve this issue i'd be glad to listen to it. Thank you!

Answer 1

[Jon]

With your definition of U, U has only one element. Note you first assign a scalar (one element) variable u=1, then you assign U to equal every element U = u(:) of u, but it only has one element, so now U also has only one element. So it doesn't make sense to ask for elements with indices greater than 1.

[Younes Alaoui]

Ok, so how should I do if I want U to have as much elements as Y? I know there is a way to do it easily, but I forgot.

[Jon]

U and Y currently both will have the same number of elements. They will each have just one element.

If you coul provide a small standalone example script to demonstrate/reproduce your problem I could probably give you some more specific guidance