This page contains listings of some R functions and commands by category.
Workspace and help
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
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
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
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
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
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
|
Matrices
Matrices
| function name
|
functionality
|
| matrix(data, nrow, ncol, byrow)
|
create a matrix
|
| rbind(...), cbind(...)
|
combine rows or columns
|
| diag(x)
|
create a diagonal matrix
|
| %*%
|
matrix multiplication
|
| nrow(A), ncol(A)
|
number of rows and columns
|
| colMeans(A), colSums(A)
|
column means or sums
|
| dim(A)
|
dimensions of x
|
| det(A)
|
determinant
|
| t(A)
|
transpose
|
| solve(A, b)
|
solution of A x == b
|
| solve(A)
|
matrix inverse
|
| array(data, dim)
|
create a multidimensional array
|
Dataframes, factors and lists
Dataframes, factors and lists
| function name
|
functionality
|
| data.frame(...)
|
create a dataframe
|
| str(x)
|
summarise structure of x
|
| names(x)
|
names of x
|
| dim(x)
|
number of rows and columns of x
|
| attach(x)
|
copy dataframe objects into workspace
|
| detach(x)
|
delete dataframe objects from workspace
|
| factor(x)
|
create a factor
|
| levels(x)
|
select levels of factor x
|
| list(...)
|
create a list
|
| unlist(x)
|
flatten list x into a vector
|
| apply(x, i, f, ...)
|
apply f over index i of array x
|
| sapply(x, f, ...)
|
apply f to x and return a vector
|
| lapply(x, f, ...)
|
apply f to x and return a list
|
| tapply(x, i, f, ...)
|
apply f to subvectors of x given by levels of factor i
|
| mapply(f, ...)
|
apply f to multiple arguments
|
Input and output
Input and output
| function name
|
functionality
|
| scan(file, what, n, sep, skip)
|
read from a file (or keyboard)
|
| read.table(file)
|
read file in table format into dataframe
|
| read.csv(file)
|
read comma separated data
|
| read.delim(file)
|
read tab-delimited data
|
| readline(prompt)
|
read a line of text from the console i.e. user input
|
| show(object)
|
display object on screen
|
| head(object)
|
first few lines of object
|
| tail(object)
|
last few lines of object
|
| print(object), object
|
print object
|
| options(digits = x)
|
display x digits in output
|
| cat(..., file)
|
concatenate and write
|
| format(x, digits, nsmall, width)
|
format x for output
|
| paste(..., sep = " ")
|
paste strings together
|
| write(x, file, append = FALSE)
|
write to a file (or screen)
|
| sink(file)
|
redirect output to a file
|
| dump("x", file)
|
write text representation of x
|
| write.table(x, file)
|
write dataframe x to a file
|
Plotting
Plotting
| function name
|
functionality
|
| plot(x, y)
|
plot y against x
|
| :type = "?"
|
determine the type:
|
| ::"p", "l", "b"
|
for points, lines or both
|
| ::"c"
|
for the lines part alone of "b"
|
| ::"o"
|
for both lines and points overplotted
|
| ::"h"
|
for vertical lines (histogram like plot)
|
| ::"s", "S"
|
for step function, across/op or reverse
|
| ::"n"
|
no data plotted, only axes
|
| :main = "title"
|
provides plot title
|
| :xlim = c(a,b)
|
set lower and upper limits of x-axis
|
| :ylim = c(a,b)
|
set lower and upper limits of y-axis
|
| :xlab = "?", ylab = "?"
|
provide label for x-axis and y-axis
|
| :pch = k
|
set shape of points (k from 1 to 25)
|
| :lwd = ?
|
set line width, default 1
|
| :col = "?"
|
set line and point colour
|
| colour(), color()
|
list R colours
|
| lines(x, y)
|
add lines to plot
|
| abline(h), abline(v)
|
draw horizontal and vertical lines
|
| points(x, y)
|
add points to plot
|
| text(x, y, labels)
|
place text on plot
|
| curve(f, from, to)
|
plot f
|
| par(?)
|
set graphical parameters:
|
| :mfrow = c(nr, nc)
|
create grid of plots with nr rows and nc columns filled by row (mfcol fills by col)
|
| :oma = c(b, l, t, r)
|
create outer margin around each plot
|
| :mar = c(b, l, t, r)
|
create margin around each plot
|
| :las = 1
|
make y-axis labels horizontal
|
| :pty = "s"
|
force the plot shape to be square
|
| :cex = x
|
magnify symbols and text by a factor x
|
| :bty = "?"
|
determine box type drawn around plot
|
Random numbers and probability distributions
Random numbers and probability distributions
| function name
|
functionality
|
| ddist(x, p1, ...)
|
P(X=x) or f(x)
|
| pdist(q, p1, ...)
|
P(X<=q)
|
| qdist(p, p1, ...)
|
p-th quantile, equivalently 100%-point
|
| rdist(n, p1, ...)
|
pseudu-random numbers
|
| dist p1, ...
|
distribution and parameters
|
| :unif min = 0, max = 1
|
uniform
|
| :binom size, prob
|
binomial
|
| :geom prob
|
geometric
|
| :hyper m, n, k
|
hypergeometric
|
| :nbinom size, prob
|
negative binomial
|
| :poist lambda
|
Poisson
|
| :exp rate
|
exponential
|
| :chisq df
|
chi square
|
| :gamma shape, rate
|
gamma
|
| :norm mean, sd
|
normal
|
| :t df
|
t distribution
|
| :weibull shape, scale
|
Weibull
|
| set.seed(seed)
|
set position in pseudo-random sequence
|
| .Random.seed
|
state if the random number generator
|
| RNGkind()
|
which random number generator?
|
| sample(x, n, replace = TRUE)
|
sample size n from x
|
Statistical tests