"Index exceeds the number of array elements"

I've been getting an index exceed the number of array elemnts (2048)

How to I solve this?

Answer 1

[Cris LaPierre]

Use an index that is not greater than the dimension you are indexing. For example, if your array is a 1x2048, you will get this error is you try to index row 2 or column 2049.

[Jarren Berdal]

I started with a 2048 x 7 array, then sorted the data into 409 x 1 array. In the workspace its says 409 x 1 double

[Cris LaPierre]

How are you indexing? That is what is causing the problem. What is the value of your index when you get the error?

[Jarren Berdal]

Pulling data from a 2048 x 7 array. Isolated some of the data into a 2048 x 1 array. Finding the mean of the data of groups of 5s. Came up with a 409 x 1 array.

error that appears " Index exceeds the number of array elements (2048) "

error in line 24

code:

17 - DATE = D(:,1);  % first column, days numbered from 1/1/1900
 %cloud of data for summ of the data in one grouping
19-  Darray(1,1) = mean(DATE(1:N)); %initial value
20 - PRICE = D(:,5); % 5th column associated with closing price
21- Parray(1,1) = mean(PRICE(1:N));
22 - for i = 1:(R)
23 -       p = (i*N);
24 - Darray((i+1),1) = mean(DATE((p+1):(p+N)));
25 -  Parray((i+1),1) = mean(PRICE((p+1):(p+N)));
end

[Cris LaPierre]

What is the value of

• R
• N (5?)

What is the size of DATE

Answer 2

[Walter Roberson]

We do not know what R is.

If we suppose R is the 409 and N is 5, then on the last iteration, when i = 409, then p = 409*5 = 2045, and p+1:p+N = 2046 : 2050, but the array is only 2048 long.

Meanwhile, when i = 1, then p=i*N = 5, and p+1:p+N is 5+1 : 5+5 = 6:10 . Notice that you have not accessed index 1:5 .

The solution:

23 -       p = (i*N);

should be

23 -       p = ((i-1)*N);