use for in matlab

Hi a question please: o1=100 o2=200 I want to write something like that:

if true
  for i=randi(O1,[1 ((50/100)*O1)])
       for j=randi(O2,[1 ((50/100)*O2)])
end

in fact, if

   IDX=randi(O1,[1 ((50/100)*O1)        and        JDX=randi(O2,[1 ((50/100)*O2)])

I want to start from IDX(1):IDX(end). like:

   for i=IDX(1):IDX(end)
    for j=JDX(1):JDX(end)

Thank you

Answer 1

[Walter Roberson]

for i = IDX
 for j = JDX
   ...
 end
end

[fatema saba]

Thank you. but I got the error:

 Warning: Size vector should be a row vector with integer elements.

[Walter Roberson]

IDX = randi(O1,[1 O1/2]);
JDX = randi(O2,[1 O2/2]);

Provided that O1 and O2 are even.

[fatema saba]

But I still get the error

 Warning: Size vector should be a row vector with integer elements.

[Walter Roberson]

I do not get that. Have you possibly changed your O1 or O2 to values that are not even? Your question asked about O1=100 O2=200 both of which are even (divisible by 2).

If one of your O1 or O2 are odd, then you need to clarify whether you want the half rounded down or rounded up. For example if your O1=101 then do you want your random vector to be length 50 (101/2 rounded down) or 51 (101/2 rounded up) ?