R help - Jun 2006 - NA values

Dear all R users,

I am wondering whether there is any way to replace all "NA" values in
a data
frame by some numerical value, suppose 1000?

Thanks and Regards

	[[alternative HTML version deleted]]

Hi

yes, but I ****do not**** recommend you to do it
> df<-data.frame(a=1:10, b=11:20)
> df[5,2]<-NA
> df
    a  b
1   1 11
2   2 12
3   3 13
4   4 14
5   5 NA
6   6 16
7   7 17
8   8 18
9   9 19
10 10 20
> df[is.na(df)]<-1000
> df
    a    b
1   1   11
2   2   12
3   3   13
4   4   14
5   5 1000
6   6   16
7   7   17
8   8   18
9   9   19
10 10   20
> 
but in that case you can not simply compute means, sums and other 
values just by e.g.

colSums(df, na.rm=T)

HTH
Petr





On 12 Jun 2006 at 18:18, Arun Kumar Saha wrote:

Date sent:      	Mon, 12 Jun 2006 18:18:33 +0530
From:           	"Arun Kumar Saha" <arun.kumar.saha at
gmail.com>
To:             	"r-help at stat.math.ethz.ch" <R-help at
stat.math.ethz.ch>
Subject:        	[R] NA values
> Dear all R users,
> 
> I am wondering whether there is any way to replace all "NA"
values in
> a data frame by some numerical value, suppose 1000?
> 
> Thanks and Regards
> 
>  [[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html
Petr Pikal
petr.pikal at precheza.cz

On 6/12/2006 8:48 AM, Arun Kumar Saha wrote:
> Dear all R users,
> 
> I am wondering whether there is any way to replace all "NA"
values in a data
> frame by some numerical value, suppose 1000?
In a vector it is easy, e.g. x[is.na(x)] <- 1000.  A dataframe is a list 
of vectors, so you could iterate through the list, using one of the 
apply functions (or even a for loop):

apply(x, 2, function(col) {col[is.na(col)] <- 1000; col} )

which is essentially a short form for

for (i in 1:ncol(x)) {
   col <- x[,i]
   col[is.na(col)] <- 1000
   x[,i] <- col
}

Duncan Murdoch
> 
> Thanks and Regards
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html

On Mon, 2006-06-12 at 18:18 +0530, Arun Kumar Saha
wrote:
> Dear all R users,
> 
> I am wondering whether there is any way to replace all "NA"
values in a data
> frame by some numerical value, suppose 1000?
> 
> Thanks and Regards
Hi, Arun,

sapply(dat, function(x) {x[is.na(x)] <- 1000; x})

e.g.:

## some dummy data
dat <- as.data.frame(matrix(rnorm(100), ncol = 10))
## add some NAs
samp <- sample(1:10, 4)
dat[samp, -samp] <- NA
dat
## replace NAs with 1000
dat <- sapply(dat, function(x) {x[is.na(x)] <- 1000; x})
dat

HTH

G
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