multi-variable looping problem

I need to perform a multi-variable loop for the following conditions and I have problem doing it

Info: initial_a = 1000 initial_b = 100 initial_c = 0.2 initial_d = 10

Equation x = 5a + b^2 + c/2 + 0.25d

program should start with initial_a does not changes but value of b changes with increment of 10 till 200, a changes with increment of 0.01 till 0.3 and d changes with increment of 1 till 20.

then in continues to by increasing value of initial_a by 100 and the same condition of b,c,d applies

the loop should end when intial_a is 20000

[José-Luis]

What have you tried so far? Sounds like your problem could be solved with four nested loops. It could also be achieved through vectorization. What's your increment step?

[Arjun]

I tried the nested loops, it kinda worked....but what do u mean by vectorization? tq

Answer 1

[Hugo]

for a=1000:100:20000
  ia=floor(a/100)-9;
  for b=100:10:200
    ib=floor(b/10)-9;
    for c=.2:.01:.3
      ic=floor(c/.01)-19;
      for d=10:1:20
        id=d-9;

          x(ia,ib,ic,id)= 5*a + b^2 + c/2 + 0.25*d
        end
      end
    end
  end

The variables ia, ib, ic, id are there just for being able to index the variable x. It would also be advisable to allocate space for x before the loops using x=zeros(191,11,11,11);

Answer 2

[Arjun]

tq very much my fren =)