Remove variable labels attached with foreign/Hmisc SPSS import functions
Question
As usual, I got some SPSS file that I've imported into R with spss.get
function from Hmisc
package. I'm bothered with labelled
class that Hmisc::spss.get
adds to all variables in data.frame
, hence want to remove it.
labelled
class gives me headaches when I try to run ggplot
or even when I want to do some menial analysis! One solution would be to remove labelled
class from each variable in data.frame
. How can I do that? Is that possible at all? If not, what are my other options?
I really want to bypass reediting variables "from scratch" with as.data.frame(lapply(x, as.numeric))
and as.character
where applicable... And I certainly don't want to run SPSS and remove labels manually (don't like SPSS, nor care to install it)!
Thanks!
Solution
You can avoid creating "labelled" variables in spss.get with the argument: , use.value.labels=FALSE.
w <- spss.get('/tmp/my.sav', use.value.labels=FALSE, datevars=c('birthdate','deathdate'))
The code from Bhattacharya could fail if the class of the labelled vector were simply "labelled" rather than c("labelled", "factor") in which case it should have been:
class(x[[i]]) <- NULL # no error from assignment of empty vector
The error you report can be reproduced with this code:
> b <- 4:6
> label(b) <- 'B Label'
> str(b)
Class 'labelled' atomic [1:3] 4 5 6
..- attr(*, "label")= chr "B Label"
> class(b) <- class(b)[-1]
Error in class(b) <- class(b)[-1] :
invalid replacement object to be a class string
OTHER TIPS
Here's how I get rid of the labels altogether. Similar to Jyotirmoy's solution but works for a vector as well as a data.frame. (Partial credits to Frank Harrell)
clear.labels <- function(x) {
if(is.list(x)) {
for(i in 1 : length(x)) class(x[[i]]) <- setdiff(class(x[[i]]), 'labelled')
for(i in 1 : length(x)) attr(x[[i]],"label") <- NULL
}
else {
class(x) <- setdiff(class(x), "labelled")
attr(x, "label") <- NULL
}
return(x)
}
Use as follows:
my.unlabelled.df <- clear.labels(my.labelled.df)
You can try out the read.spss
function from the foreign
package.
A rough and ready way to get rid of the labelled
class created by spss.get
for (i in 1:ncol(x)) {
z<-class(x[[i]])
if (z[[1]]=='labelled'){
class(x[[i]])<-z[-1]
attr(x[[i]],'label')<-NULL
}
}
But can you please give an example where labelled
causes problems?
If I have a variable MAED
in a data frame x
created by spss.get
, I have:
> class(x$MAED)
[1] "labelled" "factor"
> is.factor(x$MAED)
[1] TRUE
So well-written code that expects a factor (say) should not have any problems.
Well, I figured out that unclass
function can be utilized to remove classes (who would tell, aye?!):
library(Hmisc)
# let's presuppose that variable x is gathered through spss.get() function
# and that x is factor
> class(x)
[1] "labelled" "factor"
> foo <- unclass(x)
> class(foo)
[1] "integer"
It's not the luckiest solution, just imagine back-converting bunch of vectors... If anyone tops this, I'll check it as an answer...
Suppose:
library(Hmisc)
w <- spss.get('...')
You could remove the labels of a variable called "var1" by using:
attributes(w$var1)$label <- NULL
If you also want to remove the class "labbled", you could do:
class(w$var1) <- NULL
or if the variable has more than one class:
class(w$var1) <- class(w$var1)[-which(class(w$var1)=="labelled")]
Hope this helps!