Plotting an increasing real sequence

I am trying to plot an increasing sequence n(t) against t over an interval given in the function:

function Initialproblem(N,T,p)
    n=zeros(T,1);
    for t = 1:T
        s=t-1;
        n(t) = N*exp(-p)+n(s)*(1-exp(-p)); 
    end
    fplot(0:1:T,n_t)

I think there is an issue when I call n(s) but I need to access the element prior.

The error I am getting is "Array indices must be positive integers or logical values." Clearly a function including exp will not be a integer, but I don't know how else to perform this task.

Any help would be great

Answer 1

[Dyuman Joshi]

"I think there is an issue when I call n(s)"

You are right. When t == 1, s = t-1 == 0. And as you are using s as an index, it gives the error.

Indexing in MATLAB starts from 1 (as can be inferred from the error message).

The solution is to define the value of 1st element manually and start the for loop from t == 2.

If the value is 0, you can remove the assignment, as you have already assigned it to zero.

function Initialproblem(N,T,p)
    n=zeros(T,1);
        
    n(1) = value_of_starting_point;
    for t = 2:T
        s = t-1;
        n(t) = N*exp(-p)+n(s)*(1-exp(-p)); 
    end
    fplot(0:1:T,n_t)
end

[Benjamin Wilson]

Thanks for replying! Dyuman you are the best!