[R] fast NA elimination ?

[F Z]

Hi Ivo

Try ?na.omit

Example :

>d <- data.frame(x = c(1:5,NA), y = c(NA,3:7)) d
   x  y
1  1 NA
2  2  3
3  3  4
4  4  5
5  5  6
6 NA  7
>do<-na.omit(d)
>do
  x y
2 2 3
3 3 4
4 4 5
5 5 6

I usually pass na.omit within the data argument of a function i.e.  
m<-lm(x~y,data=na.omit(d)). In this way you don't have to store 2 datasets.

I hopw that this helps

Francisco

>From: Marc Schwartz <MSchwartz at MedAnalytics.com>
>Reply-To: MSchwartz at MedAnalytics.com
>To: ivo welch <ivo_welch at mailblocks.com>
>CC: R-Help <r-help at stat.math.ethz.ch>
>Subject: Re: [R] fast NA elimination ?
>Date: Wed, 07 Jul 2004 09:41:39 -0500
>
>On Wed, 2004-07-07 at 09:35, ivo welch wrote:
> > dear R wizards: an operation I execute often is the deletion of all
> > observations (in a matrix or data set) that have at least one NA. (I
> > now need this operation for kde2d, because its internal quantile call
> > complains;  could this be considered a buglet?)   usually, my data sets
> > are small enough for speed not to matter, and there I do not care
> > whether my method is pretty inefficient (ok, I admit it: I use the
> > sum() function and test whether the result is NA)---but now I have some
> > bigger data sets. Is there a recommended method of doing NA elimination
> > most efficiently? sincerely, /iaw
> > ---
> > ivo welch
> > professor of finance and economics
> > brown / nber / yale
>
>
>Take a look at ?complete.cases
>
>HTH,
>
>Marc Schwartz
>
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