[R] Odp: conditional data replace (recode, change or whatsoever)

2011-08-03 Thread Petr PIKAL 
Hi
 
 Hello,
 I have a big data.frame, a piece of it as follows.
 
 a   b  c   d
 1   58009   2010-11-02   0   NA
 2   114761   NA  1   2008-11-05
 3   184440   NA  1   2009-12-08
 4   189372   NA  0   NA
 5   105286   NA  0   NA
 6   186717   NA  0   NA
 7   189106   NA  0   NA
 8   127306   NA  0   NA
 9   157342   2011-04-25   0   NA
 
 I want to replace b[NA] values with 20011-07-28 where c==0. I use 
rstudio
 and i'm a novice.

I believe there are better solutions but I would use two steps

select rows where c==0 (see also FAQ 7.31)
sel-which(big.data.frame$c==0)

change NA values in b column based on sel
big.data.frame$b[sel][is.na(big.data.frame$b[sel])]-20011-07-28

Beware of data types AFAIK R can not accept 20011-07-28 as a date.

Regards
Petr

 
 
 --
 View this message in context: http://r.789695.n4.nabble.com/conditional-
 data-replace-recode-change-or-whatsoever-tp3714715p3714715.html
 Sent from the R help mailing list archive at Nabble.com.
 
 __
 R-help@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.

__
R-help@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.

Re: [R] Odp: conditional data replace (recode, change or whatsoever)

2011-08-03 Thread zcatav 

Petr Pikal wrote:
 
 Hi
 I believe there are better solutions but I would use two steps
 
 select rows where c==0 (see also FAQ 7.31)
 sel-which(big.data.frame$c==0)
 
 change NA values in b column based on sel
 big.data.frame$b[sel][is.na(big.data.frame$b[sel])]-20011-07-28
 
 Beware of data types AFAIK R can not accept 20011-07-28 as a date.
 
 Regards
 Petr
 
 

Thanks, it runs like a charm.
Replaced date format just a typo.

--
View this message in context: 
http://r.789695.n4.nabble.com/conditional-data-replace-recode-change-or-whatsoever-tp3714715p3715080.html
Sent from the R help mailing list archive at Nabble.com.

__
R-help@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.