Re: Trying to solve du/dt = i*u

[Francesco Potorti`]

>Now, my modified script (appended below) has several "for loops," and  
>I've read here on more than one occasion that it helps to vectorize  
>"for loops" to speed things up.  However, I can't see how to  
>vectorize the "for loops" in my script.  I would appreciate help with  
>this from anyone.

By having a quick look, I'd say that you should be able to vectorise
much of the code.

I illustrate one possible strategy with the first loop:

   K = 100;
   U = zeros (K, 2*K+1);
   V = zeros (2*K+1, 1);

   for k = 1:K
     for j = k+1:k+K
       U(k, j) = z(K+k+1-j);
     endfor
   endfor

You easily remove the inner loop like this:

   for k = 1:K
     U(k,k+1:k+K) = z(K:-1:1)
   endfor

I see no way of vectorising this one, but maybe others will.

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