Vocabulary

Vocabulary

The following functions outline my expectation for a working vocabulary of R functions. I don't expect you to be intimately conscious of the details of every function, but you should at least be aware that they all exist, so that if you do encounter a problem that requires a special tool, you're already aware of it. The functions come from the base and stats packages, but include a few pointers to other packages and important options.

To get the most out of this book, you should be familiar with "the basics". For data analysis, you also need I/O and special data. My current favourite reference for this level of introduction to R is the R Cookbook by Paul Teetor.

The basics

# The first functions to learn
?
str

# Operators
%in%, match
=, <-, <<-, assign
$, [, [[, head, tail, subset
with
within

# Comparison 
all.equal, identical
!=, ==, >, >=, <, <=
is.na, complete.cases
is.finite

# Basic math
*, +, -, /, ^, %%, %/%
abs, sign
acos, asin, atan, atan2
sin, cos, tan
ceiling, floor, round, trunc, signif
exp, log, log10, log2, sqrt

max, min, prod, sum
cummax, cummin, cumprod, cumsum, diff
range
mean, median, cor, sd, var
pmax, pmin
rle

# Functions
function
missing
on.exit
return, invisible

# Logical & sets 
&, |, !, xor
all, any
intersect, union, setdiff, setequal
which

# Vectors and matrices
c, matrix
# automatic coercion rules character > numeric > logical
length, dim, ncol, nrow
cbind, rbind
names, colnames, rownames
t
diag
sweep
as.matrix, data.matrix

# Making vectors 
c, rep, seq, seq_along, seq_len
rev
sample
choose, factorial, combn
(is/as).(character/numeric/logical)

# Lists & data.frames 
list, unlist
data.frame, as.data.frame
split
expand.grid

# Control flow 
if, &&, || (short circuiting)
for, while
next, break

switch
ifelse

Statistics

# Linear models 
fitted, predict, resid, rstandard
lm, glm
hat, influence.measures
logLik, df, deviance
formula, ~, I
anova, coef, confint, vcov
contrasts

# Miscellaneous tests
apropos("\\.test$")

# Random variables 
beta, binom, cauchy, chisq, exp, f, gamma, geom, hyper, lnorm, logis,
multinom, nbinom, norm, pois, signrank, t, unif, weibull, wilcox, 
birthday, tukey

# Matrix algebra 
crossprod, tcrossprod
eigen, qr, svd
%*%, %o%, outer
rcond
solve

# Ordering and tabulating 
duplicated, unique
merge
order, rank, quantile
sort
table, ftable

Working with R

# Workspace 
ls, exists, get, rm
getwd, setwd
q
source
install.packages, library, require

# Help
help, ?
help.search
apropos
RSiteSearch
citation
demo
example
vignette

# Debugging
traceback
browser
recover
options(error = )
stop, warning, message
tryCatch, try

I/O

# Output
print, cat
message, warning
dput
format
sink

# Reading and writing data
data
count.fields
read.csv, read.delim, read.fwf, read.table
library(foreign)
write.table
readLines, writeLines
readRDS, saveRDS
load, save

# Files and directories 
dir
basename, dirname, file.path, path.expand
file.choose
file.copy, file.create, file.remove, file.rename, dir.create
file.exists
tempdir, tempfile
download.file

Special data

# Date time
ISOdate, ISOdatetime, strftime, strptime, date
difftime
julian, months, quarters, weekdays
library(lubridate)

# Character manipulation 
grep, agrep
gsub
strsplit
chartr
nchar
tolower, toupper
substr
paste
library(stringr)

# Factors 
factor, levels, nlevels
reorder, relevel
cut, findInterval
interaction
options(stringsAsFactors = FALSE)

# Array manipulation
array
dim
dimnames
aperm
library(abind)