R help - Jul 2008 - Fill in NA values in vector with previous character/factor

I have a vector of data (species names) interspersed with NA values  
and I want a function to "fill in the blanks", replacing NA values  
with whatever the last species name was.

For example the vector:

 
"A","B",NA,NA,"C",NA,NA,NA,NA,"D",NA,NA.

should evaluate to:

"A" "B" "B" "B" "C"
"C" "C" "C" "C" "D"
"D" "D"


I tried to use rle() in a function to do this but have hit a brick wall.

How would YOU do this?

Many thanks,

Owen

Try this:

library(zoo)
x <- 
c("A","B",NA,NA,"C",NA,NA,NA,NA,"D",NA,NA)

na.locf(x)


On Mon, Jul 28, 2008 at 2:10 PM, Owen Jones <owen.jones at imperial.ac.uk>
wrote:
> I have a vector of data (species names) interspersed with NA values and I
> want a function to "fill in the blanks", replacing NA values with
whatever
> the last species name was.
>
> For example the vector:
>
> 
"A","B",NA,NA,"C",NA,NA,NA,NA,"D",NA,NA.
>
> should evaluate to:
>
> "A" "B" "B" "B" "C"
"C" "C" "C" "C" "D"
"D" "D"
>
>
> I tried to use rle() in a function to do this but have hit a brick wall.
>
> How would YOU do this?
>
> Many thanks,
>
> Owen
>
> ______________________________________________
> 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.
>

try function na.locf() from package 'zoo', i.e.,

library(zoo)
x <-
c("A","B",NA,NA,"C",NA,NA,NA,NA,"D",NA,NA)
na.locf(x)


I hope it helps.

Best,
Dimitris


----
Dimitris Rizopoulos
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
      http://perswww.kuleuven.be/dimitris_rizopoulos/


Quoting Owen Jones <owen.jones at imperial.ac.uk>:
> I have a vector of data (species names) interspersed with NA values and
> I want a function to "fill in the blanks", replacing NA values
with
> whatever the last species name was.
>
> For example the vector:
>
> 
"A","B",NA,NA,"C",NA,NA,NA,NA,"D",NA,NA.
>
> should evaluate to:
>
> "A" "B" "B" "B" "C"
"C" "C" "C" "C" "D"
"D" "D"
>
>
> I tried to use rle() in a function to do this but have hit a brick wall.
>
> How would YOU do this?
>
> Many thanks,
>
> Owen
>
> ______________________________________________
> 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.


Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm

maybe this is easiest way to do it:


x<-c("A","B",NA,NA,"C",NA,NA,NA,NA,"D",NA,NA);

x[is.na(x)]<- "D"; x


thanks
y




Owen Jones-3 wrote:
> 
> I have a vector of data (species names) interspersed with NA values  
> and I want a function to "fill in the blanks", replacing NA
values
> with whatever the last species name was.
> 
> For example the vector:
> 
>  
"A","B",NA,NA,"C",NA,NA,NA,NA,"D",NA,NA.
> 
> should evaluate to:
> 
> "A" "B" "B" "B" "C"
"C" "C" "C" "C" "D"
"D" "D"
> 
> 
> I tried to use rle() in a function to do this but have hit a brick wall.
> 
> How would YOU do this?
> 
> Many thanks,
> 
> Owen
> 
> ______________________________________________
> 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.
> 
> 

-----
Yasir H. Kaheil
Columbia University
-- 
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