Hello,
Arun has a point, I forgot to check the element to be replaced for a
zero. The following code will do that.
dat <- read.table(text = "
a b c d
0 1 1 0
1 1 1 1
1 0 0 1
", header = TRUE)
dat <- data.matrix(dat)
str(dat)
dat[, 1:2] <- sapply(1:2, function(i) ifelse(dat[, i] == 0 & dat[, 4] ==
0, NA, dat[, i]))
Hope this helps,
Rui Barradas
Em 02-03-2013 16:11, arun escreveu:
HI,
Not sure I understand it correctly,
data1<-read.table(text="
a b c d
0 1 1 0
1 1 1 1
1 0 0 1
",sep="",header=TRUE)
data2<- data1
data3<- data1
If i follow this logic for the 1st and 2nd columns,
data1[ data1[ , 4 ] == 0 , 1 ] <- NA
data1[ data1[ , 4 ] == 0 , 2 ] <- NA
data1
# a b c d
#1 NA NA 1 0
#2 1 1 1 1
#3 1 0 0 1
Still, the column 'b' with 0 element is left as such while and `1` in b is
replaced with NA
data2[,1][data2[,4]==0 & data2[,1]==0]<- NA
data2[,2][data2[,4]==0 & data2[,2]==0]<- NA
data2
# a b c d
#1 NA 1 1 0
#2 1 1 1 1
#3 1 0 0 1
#or you can try
data3[,1:2]<- lapply(letters[1:2],function(x) {x1<-cbind(data3[,x],data3[,4]);colnames(x1)<-
c(x,"d");x1; x1[rowSums(x1)==0,1]<-NA;x1[,1]})
data3
# a b c d
#1 NA 1 1 0
#2 1 1 1 1
#3 1 0 0 1
A.K.
----- Original Message -----
From: Anthony Damico <ajdam...@gmail.com>
To: Camilo Mora <cm...@dal.ca>
Cc: R help <r-help@r-project.org>
Sent: Saturday, March 2, 2013 6:10 AM
Subject: Re: [R] replace zeros for NA in a column based on values of another
column
you want to replace all rows where the 4th column is zero.. (data[ , 4 ]
== 0)
and you want to perform that replacement in the first column..
so try
data[ data[ , 4 ] == 0 , 1 ] <- NA
On Sat, Mar 2, 2013 at 5:26 AM, Camilo Mora <cm...@dal.ca> wrote:
Hi everyone,
Imagine that I have a data frame with four columns:
data<-
a b c d
0 1 1 0
1 1 1 1
1 0 0 1
I want to replace the zeros in columns a:b for NA only for the rows in
which column d are zero. So
a b c d
NA 1 1 0
1 1 1 1
1 0 0 1
I am trying this:
data[,1:3][data[4] == 0] <- NA
But get this error:
Error in `[<-.data.frame`(`*tmp*`, Data[4] == 0, value = NA) :
only logical matrix subscripts are allowed in replacement
Does anyone knows the reason of this error or is there an alternative to
replace the values in one column based on the values of another?
Thanks,
Camilo
Camilo Mora, Ph.D.
Department of Geography, University of Hawaii
http://www.soc.hawaii.edu/**mora/ <http://www.soc.hawaii.edu/mora/>
______________________________**________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/**listinfo/r-help<https://stat.ethz.ch/mailman/listinfo/r-help>
PLEASE do read the posting guide http://www.R-project.org/**
posting-guide.html <http://www.R-project.org/posting-guide.html>
and provide commented, minimal, self-contained, reproducible code.
[[alternative HTML version deleted]]
______________________________________________
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.
______________________________________________
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.
