vectorization

Hi, can any body suggest as to how I can vectorize this little bit of code:

% for i = 2:n % f(i) = f(i-1)+dx*x(i-1); % end

where, f = zeros(1,n); dx = 1/(n-1); x = 0:dx:1;

appreciate any help, because I am kind of stuck and right now don't think it can be done at all. Thanks, Asit

Answer 1

[Andrei Bobrov]

dx = 1/(n-1); 
x = 0:dx:1;
f = [0 cumsum(dx*x(1:end-1))]

[Titus Edelhofer]

You might also use

x = linspace(0, 1, n);

[Asit]

Hi Andrei, thanks a lot for your response.

It would be very helpful for using in situations with multiple such loops.

I was so busy trying to trick a way out that I forgot about the built in cumulative summation feature. :P

As others might have guessed, for this particular example though, the loop seems to be slightly faster.

Titus: I am bit shaky on the differences between using 1:dx:b and linspace. Generally, if I know the number of divisions I want, I go for linspace, if I know their size, I go for the a:dx:b thing. In this case both are known, though linspace requires 1 less operation. Any other advantages I am missing?

Thank you both,

a.