List of R functions: Difference between revisions

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This page contains listings of some R functions and commands by category.

**Workspace and help**
function name	functionality
getwd()	get working directory
setwd(dir)	set working directory to dir
help(topic), ?topic	get help on topic, usually function name
help.search("keyword")	search for help
help.start()	HTML help start page
demo()	list available demonstrations
save(..., file), load(file)	save and load objects
savehistory(file), loadhistory(file)	save and load command history
source(file)	execute commands from file
list.files(dir), dir(dir)	list files in directory dir
q()	quit R

**Objects**
function name	functionality
mode(x)	mode of x
ls(), objects()	list objects in memory
rm(x), rm(list = ls())	remove x or all objects
exists(x)	test if object x exists in memory
as.numeric(x), as.list(x), ...	coerce mode of object x
is.numeric(x), is.na(x), ...	test mode of object x
identical(x, y)	test if objects are identical
return(invisible(x))	return invisible copy (doesn't print)

**Packages**
function name	functionality
install.packages(name)	download and install package name
download.packages(name, dir)	download package name into dir
library(name), require(name)	load package name
data(name)	load dataset name
.libPaths(dir)	add directory dir to library paths
sessionInfo()	list loaded packages

**Flow and control and function definition**
function name	functionality
if(logical_expression) expression_1 else expression_2	if then else
for (x in vector) expression	loop through elements of vector as x
while (logical_expression) expression	while loop
name <- function(input1, ...) {expression_1; ...; return(output))	function definition
stop(message)	cease processing and print message
browser()	stop to inspect objects for debugging
system.time(expression)	report runtime for expression

**Mathematical and logical operators and functions**
function name	functionality
+, -, *, /, ^, %%, %/%	algebraic operators, %% for remainder of integer division, %/% for integer division i.e. rounded down to 0 decimal places
<, >, <=, >=, ==, !=	comparison operators
, !	logical operators (and, or, not)
&&, \|\|	and/or evaluated progressively from left
xor(A, B)	exclusive or (A or B but not both)
ifelse(condition, x, y)	choose x or y elementwise
sin(x), cos(x), tan(x)	sine, cosine and tangent
asin(x), acos(x), atan(x)	inverse sine, cosine and tangent
exp(x), log(x)	exponential and logarithm base e
sqrt(x)	square root
abs(x)	absolute value
pi	3.145926...
ceiling(x)	smallest integer >= x
floor	largest integer <= x
all.equal(x, y)	almost equal
round(x, k)	round x to k digits
deriv(expression, vars)	symbolic differentiation

**Vectors**
function name	functionality
x[i]	select subvector using index vector
x[logical], subset(x, subset)	select subvector using logical vector
c(...)	combine vectors
seq(from, to, by), from:to	generate an arithmetic sequence
rep(x, times)	generate repeated values
length(x)	length of x
which(x)	indices of TRUE elements of x
sum(...)	sum over vector(s)
prod(...)	product over vector(s)
cumsum(x), cumprod(x)	cumulative sum and product
min(...), max(...)	minimum and maximum
sort(x)	sort a vector
mean(x)	sample mean
var(x), sd(x)	sample variance and standard deviation
order(x)	rank order of elements of x

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 | logical operators (and, or, not)
 |-----
-| &&, ||
+| &&, <nowiki>||</nowiki>
 | and/or evaluated progressively from left
 |-----