I think you can replace your 'for' loop with vectorized operations:
if(NW > 0){
Rnorm <- Rnorm + sum(abs(Y[Nstart:(Nstart + NW - 1)]) ^ 2)
}
On Sun, Apr 26, 2009 at 1:42 PM, <mau...@alice.it> wrote:
> After a year my R programming style is still very "C like".
> I am still writing a lot of "for loops" and finding it difficult to recognize
> where, in place of loops, I could just do the
> same with one line of code, using "sapply", "lapply", or the like.
> On-line examples for such high level function do not help me.
> Even if, sooner or later, I am getting my R scripts to do what I expect, I
> would really like to shake my C programming style off.
> I am staring at my R script and thinking "how can I improve it ?"
> For instance, I have a lot of loops similar to the following one and wonder
> whether I can replace them with a proper call to a high level R function that
> does the same:
>
> Nstart <- Nfour/(2^Lev) + 1
> Nfinish <- Nstart -1 + Nfour/(2^Lev)
> LengLev <- Nfinish - Nstart + 1
> NW <- floor(LengLev*N/Nfour)
> if(NW > 0){
> for(j in Nstart:(Nstart + NW -1)){
> Dw <- abs(Y[j])
> Rnorm <- Rnorm + Dw^2
> }
> }
>
>
> Thank you very much for helping me get better.
> Maura
>
>
>
>
>
> tutti i telefonini TIM!
>
>
> [[alternative HTML version deleted]]
>
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--
Jim Holtman
Cincinnati, OH
+1 513 646 9390
What is the problem that you are trying to solve?
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