[R] Odp: Data frame modification

[Petr PIKAL]

Hi

r-help-bounces at r-project.org napsal dne 28.07.2010 11:30:48:

> Hi
> 
> I am trying to modify a data frame D with lists x and y in such a way 
that if 
> a value in x==0 then it should replace that value with the last not zero 
valuein x. I.e.
> 
> for loop over i{
> if(D$x[i]==0)
>      D$x[i]=D$x[i-1]
> }
> 
> The data frame is quite large in size ~ 43000 rows. This operation is 
taking a
> large amount of time. Can someone please suggest me what might be the 
reason.

Bad programming practice? I would suggest to use zoo package and na.locf 
function after changing all zero values to NA.

Regards
Petr

> 
> Thanks
> Regards
> Siddharth
> Sent on my BlackBerry® from Vodafone
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide 
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.