Index in position 1 exceeds array bounds. Error in dt (line 41) del(i,N) = del(i,N-i);

clc;
clear all;
close all;
n=100;
r=10;
a=1;
b=3;
p=[];
q=[];
del=[];
d_t=[];
for i = 1:n
    %p(i) = i
    %q(i) = n - p(i)
    for N = 1:r
        p(i,N) = i;
        q(i,N) = n - p(i,N);
        %disp(p(i,N))
        %disp(q(i,N))
        %disp("The forwarding ratio is, fr = ");
        fr(i,N) = p(i,N)/(p(i,N)+q(i,N));
        %disp(p(i,N))
        %disp(q(i,N))
        disp("The number of packets transmitted are, p = ");
        disp(p(i,N))
        disp("The number of packets dropped are, q = ");
        disp(q(i,N))
        disp("The forwarding ratio is, fr = ");
        disp(fr(i,N)) 
        while N > 1
            if fr(i,N-i) > fr(i,N)
                del(i,N) = del(i,N-i) + a*(fr(i,N-i) - fr(i,N));
                disp("The values of the 'del' parameter are, deln = ")
                disp(del(i,N))
            end         
            if fr(i,N-i) < fr(i,N)
                del(i,N) = del(i,N-i) + b*(fr(i,N-i) - fr(i,N));
                disp("The values of the 'del' parameter are, deln = ")
                disp(del(i,N))
            else
                del(i,N) = del(i,N-i);
                disp("The values of the 'del' parameter are, deln = ")
                disp(del(i,N))
            end
            d_t = fr(i,N) * cos((22/14)*del(i,N));
            %disp("The direct trust values are ,d_t = ")
            %disp(d_t)
        end
        %d_t = fr(i,N) * cos((22/14)*del(i,N));
        disp("The direct trust values are ,d_t = ")
        disp(d_t)
    end
end

Answer 1

[KSSV]

This error occurs, when you try to extxract more number of elements than present in the array.

% Example
A = [1 2] ;
A(1)  % no error 

ans = 1

A(2)   % no error 

ans = 2

A(3)  % error, becuase there are only two elements. 

Index exceeds the number of array elements. Index must not exceed 2.

Similarly, in your case the variable del is of size 1x1 and you are extracting del(1,N) with N = 2. So error pops.

Think your problem and code it properly. You should initialize the arrays inside the loop well before the loop.