Assigning a 2D matrix

I have to create a 2D matrix, where the row number is unknown. I will have to find the row number.

Say, for i=1:5

for j=1:3

I want to create a 2D matrix with 2 columns, where the entries will be like [i j]

How should I write the code?

[Raj]

Your question is not at all clear. What exactly are you looking for? Can you give a better example?

[Sariha Azad]

I want the iterators as entries, as for i=1:2,for j=1:2, matrix=[1 1;1 2;2 1;2 2]

Answer 1

[KSSV]

If you know column numbers and don;t know row number; you can initialize as below;

iwant = zeros([],col) ; 

If you know row numbers and dont know column number; you can initialize as below;

iwant = zeros(row,[] ; 

But, it seems in your case:

iwant = zeros(5,3) ; 
for i=1:5
    for j=1:3
        iwant(i,j) = rand ; 
    end
end

[Sariha Azad]

I want to make like for i=1:2,for j=1;2,

iwant=[1 1;1 2; 2 1; 2 2]

Answer 2

[Sariha Azad]

Well, I got this one.

a=[0 0];
for i=1:5
    for j=1:3
        a=[a;i j];
    end
end
disp(a)

Answer 3

[Stephen23]

Simpler without a loop:

>> [X,Y] = ndgrid(1:3,1:5);
>> M = [X(:),Y(:)]
M =
   1   1
   2   1
   3   1
   1   2
   2   2
   3   2
   1   3
   2   3
   3   3
   1   4
   2   4
   3   4
   1   5
   2   5
   3   5

[Sariha Azad]

Thanks