Loop that creates arrays

Hey folks I'm trying to write a loop that will create arrays filled with zeros and I'd like it so that each array can be identified somehow (i.e. subscripts, unique name for each array).

In Maple, I would have done something like this... for k to 10 do A[k] := Array(1..10): end do:

which would create 10 arrays and each could be indivually accessed using A[k]. (i.e. A[1] is an array of size 10, A[2] is a different array of size 10 etc...)

Is there a way to do this in Matlab?

Answer 1

[Jos (10584)]

If all the arrays are vectors (=1D arrays in matlab) you can store them in a matrix (=2D array).

% Pre-allocate an matrix with four "vector arrays"  of 6 elements each
A = zeros(4,6) ;

Here is an example to fill this array

for k=1:4
  A(k,:) =  (1:6) ./ k ; % just an example
end

To access a "array" (vector!) use indexing B = A(2,:) % get second row

If the vectors have different sizes, you need to look into cells and/or structs

A = {1:3 1:10 1:5} % a cell with 3 vectors
A{3} % third vector

[Walter Roberson]

Small modification: instead of

A(k,:) = [1:6) / k;

better is

A(k,:) = (1:6) ./ k;

1:6 is automatically a vector and does not need [] around it. And using ./ instead of / is good practice as is makes it clearer that you are expecting element-by-element division rather than matrix division.

[Jos (10584)]

I completely agree, Walter. I have changed the answer accordingly.

Answer 2

[Sean de Wolski]

 doc cell

You need cell arrays.

Answer 3

[Brian]

Ok great thanks for that.

I think I'll go with Jos' option as all vectors should be the same size.

[Walter Roberson]

These remarks are better done as Comments on the appropriate answer.

Answer 4

[Hillary Omuga]

write a for loop to create an array named X. Each value in X is equal to its assaciated index value (a.k.a its position in the array) times 12 minus 1. The size of X is 52*1