Terms & Abbreviations in R

Table below presents a comprehensive glossary of R terms and abbreviations used in all vignettes by Tingting Zhan.

https://rpubs.com/tingtingzhan

R terminology and nomenclature could be drastically different from that of mathematics and statistics. Readers are strongly advised to read closely from the reference links in this table, most of which point to webpages on search.r-project.org, cran.r-project.org, adv-r.hadley.nz and en.wikipedia.org.

Term / Abbreviation	Description
CRAN, R	The Comprehensive R Archive Network, https://cran.r-project.org
Depends, Imports, Suggests, Enhances	Writing R Extensions, Section 1.1.3 Package Dependencies
Symbols
|>	Forward pipe operator, introduced since R version 4.1.0
~	Tilde operator, to separate the left- and right-hand sides in a formula
.	Dot symbol, to denote the remaining variables contained in a data.frame. See formula and terms.formula for details.
:	Colon operator for interaction of factors, see section Details of formula documentation
/	Forward slash operator for nested grouping structure, see section Details of formula documentation
\	Shorthand syntax for anonymous functions, introduced since R version 4.1.0
::, :::	Double and triple colon operators, explicitly-namespaced function or object
$	Extract parts of an object
A
abline	Add straight line (by intercept and slope) to a plot
abs	Absolute value
addmargins	Add margins to arrays
aov, anova	Analysis-of-variance (ANOVA) model; ANOVA table
approxfun	Linear interpolation
args	Argument list of a function
attr, attributes	Attributes
B
dbinom, pbinom, qbinom	Binomial density, probability, quantile
body	Body of a function
boxplot	Box plot
C
call	Unevaluated expression
class	Object class
closure	https://www.r-bloggers.com/2012/12/closures-in-r-a-useful-abstraction/, http://adv-r.had.co.nz/Functional-programming.html#closures
chisq.test	Pearson’s \chi^2-test
confint	Confidence intervals for model parameters
contour	Contour line, https://en.wikipedia.org/wiki/Contour_line
cor, cov, cov2cor	Correlation matrix, variance-covariance matrix, and their conversion
cut	Convert numeric to factor
D
data.frame	Data frame
.Deprecated, .Defunct	R function retirement
density	Kernel Density Estimation
deparse, deparse1	Expression deparsing, i.e., turn unevaluated expressions into character scalar or vector
diag	Matrix diagonals
dim	Dimensions
dist	Distance matrix
duplicated	Duplicate elements
E
ecdf	Empirical cumulative distribution function
emptyenv	Empty environment
environment, as.environment	(Coerce to an) environment
eval	Evaluate an R expression
exp	Exponential
export	Export tags in NAMESPACE
expression	Unevaluated expressions
F
factor	Categorical object, a.k.a., factor
file.size	File size in bytes
fisher.test	Fisher’s exact test
(one-sided) formula	Formula, or one-sided formula
foobar	Placeholder; https://en.wikipedia.org/wiki/Foobar
formals	Formal arguments of R function
function	R function definition
G
ggplot	Elegant data visualisations using the grammar-of-graphics, from package ggplot2 (Wickham 2016)
glm	Generalized linear model
globalenv, .GlobalEnv	Global environment
H
head	First parts of an object
I
identical	Exact equality in R
inherits	Class inheritance
Inf, is.finite	Positive infinity \infty
J
K
kable	Tables in LaTeX, HTML, markdown and reStructuredText, from package knitr (Xie 2025)
kerndens	Kernel density, stats::density.default()$y
kmeans	k-means clustering (Hartigan and Wong 1979)
L
L-suffix	Create integer constant; https://adv-r.hadley.nz/vectors-chap.html#atomic-vectors
labels	Labels from object
language	R language object
length	Length of an object
lengths	Lengths of list or vector elements
levels	Levels of a factor
library	Loading/attaching packages
list, listof	Lists of objects
list2env	Create an environment containing all list components as objects
listof	List of objects
lm	Linear model
dlnorm, plnorm, qlnorm, rlnorm	Log-normal density, probability, quantile and random number generator
log, log1p, log2, log10	\log(x) and \log(x+1) transformations
logistic	Logistic regression model, stats::glm(., family = binomial('logit'))
M
.Machine	Numerical characteristics of the machine R is running on, e.g., 32-bit integers and IEC 60559 floating-point (double precision) arithmetic
mapply	Apply a function to multiple list or vector arguments
match	Value matching
match.call	Argument matching
matrix	Matrices
mc.cores	Number of central processing unit (CPU) cores to use for parallel computing
mean	Arithmetic mean
median	Median value
merge, merge.data.frame	Merge two data.frames
message	Diagnostic message printed in R console
missing	R function not having a default value for a formals argument
mode of storage	Storage mode
mode of vector	Vector mode
N
NA, NA_real_	Not-Available; missing logical/double values
NaN	Not-a-Number
na.fail, na.omit, na.exclude, na.pass	Handle missing values in R objects
names	Names of an R object
dnbinom, pnbinom, qnbinom, rnbinom	Negative binomial density, probability, quantile and random number generator
ncol, nrow	Number of rows/columns of an array
dnorm, pnorm, qnorm, rnorm	Normal density, probability, quantile and random number generator
numeric	numeric, i.e., double-precision object
O
object.size	Memory allocation
optimize, optimise, optim	Brent–Dekker in one-dimensional optimization; Nelder-Mead, quasi-Newton, conjugate-gradient in higher-dimensional optimizations
ordered	Ordered factor
P
parent.env	Parent environment
paste, paste0	Concatenate character strings
persp	Perspective plot, https://en.wikipedia.org/wiki/Perspective_(graphical)
pi	Mathematical constant \pi, ratio of a circle’s circumference to its diameter
plot	Plot
pmax, pmin	Point-wise maxima and minima
dpois, ppois, qpois	Poisson density, probability, quantile
predict	Model prediction
.Primitive	Primitive, i.e., internally implemented, function
prop.test	Pearson’s \chi^2-test on proportions
Q
quantile	Quantile
R
range	Range of values
read.csv	Read comma-separated-value .csv files
recycle	Recycling, https://r4ds.had.co.nz/vectors.html#scalars-and-recycling-rules
rep	Replicate elements
replicate	Repeated evaluation of an expression
return	R function return
S
S3, generic, UseMethod, methods, getS3method	S3 object oriented system, https://adv-r.hadley.nz/s3.html
S4, isS4, setClass, setGeneric, setMethod, getMethod	S4 object oriented system, https://adv-r.hadley.nz/s4.html, implemented in package methods shipped with R version 4.5.1 (2025-06-13)
sample, sample.int	Random sampling
save, saveRDS, xz	Save with xz compression
sd	Standard deviation
search	Search path for R objects
seed, set.seed	Random number generation seed
seq, seq.int	Sequence generation
signature	Tools for managing S4 generic functions
sort	Sorting vectors
sort_by	Sort an object by some criterion
splinefun	Spline interpolation
split	Divide into groups
stopifnot	To ensure the truth of R expressions
str2lang	To parse R expression
subset	Subsets of object by conditions
summary	Summaries of an R object
suppressPackageStartupMessages	To suppress packageStartupMessage
suppressWarnings	Suppress warning messages
symbol, name	Names and symbols to refer to R objects
T
t, t.default	Transpose
t.test	Student’s t-test
table	Cross tabulation
tail	Last parts of an object
tempfile	Create names for temporary files
tryCatch	Condition handling and recovery
typeof	R internal type or storage mode of any object
U
unclass	Remove S3 'class' attribute
uniroot	One dimensional root-finding
update	Update and re-fit a model call
V
var	Variance
var.test	F-test to compare variances
vector	Vector
W
with, with.default	To evaluate an expression in a local environment
within, within.data.frame	To evaluate an expression in a local environment and makes modifications to the environment
X
xtabs	Cross tabulation
Y
Z

1 References

Hartigan, John A., and M. A. Wong. 1979. “A K-Means Clustering Algorithm.” Journal of the Royal Statistical Society: Series C (Applied Statistics) 28 (1): 100–108. https://doi.org/10.2307/2346830.

Wickham, Hadley. 2016. ggplot2: Elegant Graphics for Data Analysis. Springer-Verlag New York. https://ggplot2.tidyverse.org.

Xie, Yihui. 2025. knitr: A General-Purpose Package for Dynamic Report Generation in R. https://yihui.org/knitr/.