**(1) What’s in a library?** The answer
is that many things can be contained in a library. The libraries
are bundles of code used to conduct analysis, create graphs,
etc. Libraries usually also contain some data which can be
loaded and used for a library provided example. At this point,
you’re likely thinking, so what; how do I use what’s in a
library? Well, the bad news is that you need to know what is in
a particular library before you can use it. The good news, of
course, is that it’s easy to discover what’s in a particular
library. This leads us to one of the many ways we can seek help
in R. Working from previous notes, let’s take a look at the base
library which comes installed with the base installation of R
and loads upon start up of the program R. In the console, type
the following and hit the enter key:

help(base)

There are some things to notice in the new
help window. First, at the top of the window; you’ll see the
topic you asked for help on (typically a function), the package
in which this help query topic is found, and R Documentation
which is where this help comes from. The key information for
this particular library help is what the library does or what
can it do; which is displayed in the details section.

This package contains the basic
functions which let R function as a language: arithmetic,
input/output, basic programming support, etc.

Also note that this is a rare instance when
the package help does not contain a list of the functions
available in the package. However, it does tell us what to do to
get the complete list of functions:

library(help=”base”)

which does give us a complete list of
functions and a brief description of their use. So, what is a
function? Well, let’s take a look at:

help(“function”)

This help window is more typical of what
you’ll see when using the console help function. There are key
elements here which appear in most help documentation; those
listed in red (e.g. description, usage, arguments, details,
etc.). Especially important is what we find at the bottom of the
help window; the examples. Although a bit sophisticated for us
right now; what we need to know is that all examples listed in
these types of help windows can be copied and pasted into the
console and they will work—and importantly can then be modified
for our particular use. We will use this approach in later notes
to see how to do a particular analysis and apply it to our own
data.

**(2) Finding the right library.** If we
are interested in finding a library that will allow us to do
some task or analysis; then we have a multitude of choices for
tracking down what library we need or want given the likelihood
of multiple libraries able to do a given task. If we start by
clicking on the ‘Help’ button in the task bar at the top of the
console, we find a variety of help options. Two of my most
frequently used strategies for finding help are (1) ‘HTML help’
which opens your default browser to the online R help index and
(2) ‘Search help…’ which searches help files for whatever topic
you enter. First, a note of caution; if you have all the
available packages downloaded and installed, the ‘Search help…’
will take a minute or more to collect all the results for just
about any topic you search, often resulting in a large list of
returns. For this reason, I typically use the HTML help first,

because I can click on the ‘Search Engine &
Keywords’ to look for packages, functions, or other forms of
information on a particular topic; or I can click on ‘Packages’
to review the packages’ descriptions and then click on and
review a particular package’s documentation and related
functions. There are other ways of finding help, often more
efficient; such as searching
Google using “R xxxxxxx” where xxxxxxx is the topic of
interest, or using the
Rseek search engine. Using Google will inevitably lead you
to one of the many very useful blogs created by R users who, not
long ago were in the exact same situation you might be…looking
for help with some function or library. Also keep in mind there
are several R Reference Cards available; I have
this one posted on the
web page because, I prefer it to others. Of course, there
are also the help options in the R console: ‘FAQ on R’, ‘FAQ on
R for Windows’, and the help ‘Manuals (in PDF)’ – all of which
should be considered recommended reading.

It is often intimidating to see how much
help is available and realize finding what you want can become
an adventure in and of itself. But, imagine how ridiculous
someone might find it if we complained about having too much
help available for a software package we were learning. ?.?.?