[R] Variable and value labels

[Anupam Tyagi]

Thanks again, Avi. I will read up more on factors.

On Thu, 13 Jul, 2023, 8:51 pm , <avi.e.gross using gmail.com> wrote:

> Anupam,
>
>
>
> Thanks for explaining you are talking about factors.
>
>
>
> I see my friend Adrian has pointed out reasons you may want to use a
> package he built called “declared” but my answer will be within the regular
> R domain as you asked.
>
>
>
> You should read up a bit on factors in a book, not just blindly searching.
> A factor, loosely speaking started off as a mixture of the original values
> as characters and a numbered vector referencing them. When you want the
> original labels, you can see them and when you want the integer indices you
> can see them.
>
>
>
> > greek <- c("Alpha", "Beta", "Gamma", "Alphabeta", "Beta", "Alpha",
> "Alpha Male")
>
> > greek
>
> [1] "Alpha"      "Beta"       "Gamma"      "Alphabeta"  "Beta"
> "Alpha"
>
> [7] "Alpha Male"
>
> >
>
> > facgreek <- factor(greek)
>
> > facgreek
>
> [1] Alpha      Beta       Gamma      Alphabeta  Beta       Alpha
> Alpha Male
>
> Levels: Alpha Alpha Male Alphabeta Beta Gamma
>
> >
>
> > levels(facgreek)
>
> [1] "Alpha"      "Alpha Male" "Alphabeta"  "Beta"       "Gamma"
>
> > labels(facgreek)
>
> [1] "1" "2" "3" "4" "5" "6" "7"
>
> > str(facgreek)
>
> Factor w/ 5 levels "Alpha","Alpha Male",..: 1 4 5 3 4 1 2
>
> > as.numeric(facgreek)
>
> [1] 1 4 5 3 4 1 2
>
>
>
> You can play with all kinds of things in base R such as getting the nth
> item as a label, or finding all the items currently mapped to the key of 1
> and so on.
>
>
>
> > as.numeric(facgreek)
>
> [1] 1 4 5 3 4 1 2
>
> > facgreek[5]
>
> [1] Beta
>
> Levels: Alpha Alpha Male Alphabeta Beta Gamma
>
> > facgreek[as.numeric(facgreek) == 1]
>
> [1] Alpha Alpha
>
>
>
>
>
> > as.character(facgreek)
>
> [1] "Alpha"      "Beta"       "Gamma"      "Alphabeta"  "Beta"       "Alpha"
>
> [7] "Alpha Male"
>
> > as.integer(facgreek)
>
> [1] 1 4 5 3 4 1 2
>
>
>
>
>
> Now when plotting, it depends on what you use. Base R comes with the usual
> plot functions as well as others like lattice and there are packages like
> ggplot2. Some of these may even convert a vector into a factor internally.
> In some cases, you may want to tell it to use a factor in a certain way,
> such as by re-ordering the order of the levels of a factor so the display
> is graphed in that order.
>
>
>
> And as I answered another person, some graphing functions allow you to do
> other kinds of labeling on top of the plot that may meet your needs.
>
>
>
> I may be the opposite of you as I did not use R much before 2003. 😉
>
>
>
> But seriously, we often are like new users even when we once knew a bit
> about something. The R from before 2003 (or was it S?) has evolved quite a
> bit. If, like me, you have used lots of other computer languages in
> between, then they often blend in your mind as they have overlapping
> paradigms and methods and of course quirks.
>
>
>
> And, of course, I sympathize with adjusting from other environments
> designed for somewhat more specific purposes like Stata as R is more of a
> general purpose programming language. Often people start with those others
> and then come to R because they need to be able to do more or just
> fine-tune things or …
>
>
>
>
>
>
>
> *From:* Anupam Tyagi <anuptyagi using gmail.com>
> *Sent:* Thursday, July 13, 2023 2:51 AM
> *To:* avi.e.gross using gmail.com
> *Cc:* r-help using r-project.org
> *Subject:* Re: [R] Variable and value labels
>
>
>
> Thanks, Avi. By labels I mean human readable descriptions of variables and
> values of factor variables. In a plot, I want labels to be used
> for labelling axes on which a factor is plotted, and variable labels for
> axes names/descriptions in a plot. I may have borrowed the terminology of
> variable and value labels from Stata software, which I use.
>
>
>
> I use a lot of packages. So, I have nothing against packages. But for
> labelling, I sometimes worry that I may get tied to a package for something
> as basic as assigning labels, and some function/packages may not pick up
> the labels correctly/well when plotting or displaying results. Maybe I am
> worried for nothing.
>
>
>
> I have not used R much after 2003. In the past few months I have begun to
> use R again with R Studio, mostly for plotting and visualization of data.
> So, you can think of me as a new user.
>
>
>
> On Thu, 13 Jul 2023 at 00:14, <avi.e.gross using gmail.com> wrote:
>
> Anupam,
>
> Your question, even after looking at other messages, remains a bit unclear.
>
> What do you mean by "labels"? What you mean by variables and values and how
> is that related to factors?
>
> An example or two would be helpful so we can say more than PROBABLY.
> Otherwise, you risk having many people here waste lots of time sending
> answers to questions you did not ask.
>
> And why an insistence on not using packages? If you are doing something for
> a class, sure, you may need to use the basics you were supposedly taught in
> class or a textbook. Otherwise, a good set of packages makes code much
> easier to write and often more reliable. Realistically, quite a bit of what
> some call base R is actually packages deemed useful enough to be included
> at
> startup and that can change.
>
> If you are new to R, note you can attach arbitrary attributes to a variable
> and you can have things like named lists where some or all the items have
> names as an attribute.
>
> Factors are part of base R and are a completely different concept. You can
> use base R to get or set the base levels of a factor and many other things
> and there are advantages sometimes in using a vector in factor mode than
> plain but also sometimes disadvantages.
>
> If you ask a more specific and properly explained question, maybe we can
> help you.
>
> Specifically, please tell us how you plan on using your labels. As an
> example, if I make a named list like this:
>
> mylist <- list(pi=3.14, e=2.7, 666)
>
> then I can access all elements as in mylist[[2]] without a name but
> mylist$pi lets me access that item by name and mylist[["e"]] and I can also
> change the current values similarly. But without explaining what you want,
> my explanation likely is not what you need.
>
> But do note that even if you do not USE a package, you can sometimes use it
> indirectly by examining the code for a function you like. If it is
> primarily
> written in R, you may see how it does something and take a part of the code
> and use it yourself.
>
>
>
> -----Original Message-----
> From: R-help <r-help-bounces using r-project.org> On Behalf Of Anupam Tyagi
> Sent: Tuesday, July 11, 2023 11:49 PM
> To: r-help mailing list <r-help using r-project.org>
> Subject: [R] Variable and value labels
>
> Hello,
>
> is there an easy way to do variable and value labels (for factor variables)
> in base-R, without using a package. If not, what is an easy and good way to
> do labels, using an add-on package.
>
> --
> Anupam.
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>
>
>
>
> --
>
> Anupam.
>

	[[alternative HTML version deleted]]