Vectorization of a for loop

Hello,

I have to do a large calculation and the next foor loop takes like 99% of runtime in the script:

for n = 1:iteraciones-1 
   x(n+1) = a - x(n)^2 + b*y(n); 
   y(n+1) = x(n); 
end

I've read that if I manage to vectorize it, it will improve my code performance, but im stuck with

x(1) = 1;
y(1) = 1;
x(2) = a - x(1)^2 + b*x(1);

for n = 2:iteraciones-1 
   x(n+1) = a - x(n)^2 + b*x(n-1);
end

y(2:iteraciones) = x(1:iteraciones-1);

And I cant think of a way to vectorize that for loop since it uses previous generated values

If someone could take the time to figure this out or link a good resource on how to vectorize, it would be much apreciated

Thanks in advice :)

[darova]

I think your code can't be vectorized. As your value of x(i+1) depends on previous x(i)

Answer 1

[Aditya Patil]

I understand that you want to vectorize the for loop to improve performance.

However vectorization of for loops requires that each iteration is independent of each other. This is not the case in your code, as x(n + 1) depends upon x(n). Hence I think it is not possible to vectorize this code.

[David Valle]

Alright, what a pity.

Anyways, thank you for your answer :)