[R] Variable and value labels

[Viechtbauer, Wolfgang (NP)]

For value labels, factor() provides the necessary machinery. For variable labels, one could make use of comment() (something that not too many people seem to know about). To illustrate:

# look at the mtcars dataset
mtcars

# turn 'am' into a factor and use labels for the two possible levels thereof
mtcars$am <- factor(mtcars$am, levels=c(0,1), labels=c("automatic","manual"))
mtcars

# add a variable label via comment()
comment(mtcars$am) <- "Type of transmission"

# extract all the variable labels
sapply(mtcars, comment)

Best,
Wolfgang

>-----Original Message-----
>From: R-help [mailto:r-help-bounces using r-project.org] On Behalf Of Anupam Tyagi
>Sent: Wednesday, 12 July, 2023 14:11
>To: Martin Maechler
>Cc: r-help mailing list
>Subject: Re: [R] Variable and value labels
>
>Thanks. Sorry, I have not consulted help pages, but did a web search. Web
>search results are referring to some package or the other for doing labels.
>Thanks for letting me know that this can be done in base-R. I will try to
>find the relevant information in R documentation.
>
>On Wed, 12 Jul, 2023, 1:33 pm Martin Maechler, <maechler using stat.math.ethz.ch>
>wrote:
>
>> >>>>> Anupam Tyagi
>> >>>>>     on Wed, 12 Jul 2023 09:18:55 +0530 writes:
>>
>>     > Hello,
>>
>>     > is there an easy way to do variable and value labels (for
>>     > factor variables) in base-R, without using a package.
>>
>> Yes, there are many.
>> How many help pages (in R , i.e. base-R)  did you consult?
>>
>> Very general questions as the above are not very useful,
>> because typically the only concised answer can be yes/no.
>>
>>
>>     > If not, what is an easy and good way to do labels, using an
>>     > add-on package.
>>
>>
>>     > --
>>     > Anupam.