Documentation on topic. Special characters need to be quoted, e.g. ?'&&'.

Search the help system

The names of all objects in the search list matching the regular expression "topic"

Start the HTML version of help

Generic function to give a "summary" of x, often a statistical one.

Display the internal structure of an R object

Show objects in the search path; specify pat="pat" to search on a pattern

str for each variable in the search path

Show files in the current directory

Show S3 methods of x

List all the methods to handle objects of class x

Search a database of help packages for functions and return a data.frame (requires sos package)

Task views provide summaries of R resources for a given domain. Groups of packages can be installed quickly via the ctv package.

• FAQ
• R Functions for Regression Analysis
• R Functions for Time Series Analysis, by Vito Ricci
• R Reference Card for Data Mining, by Yanchang Zhao
• R Reference Card by Jonathan Baron

Left assignment, binary

Right assignment, binary

Left assignment, but not recommended

Left assignment in outer lexical scope; not for beginners

List subset, binary

Minus, can be unary or binary

Plus, can be unary or binary

Tilde, used for model formulae

Sequence, binary (in model formulae: interaction)

Refer to function in a package, i.e, pkg::function; usually not needed

Multiplication, binary

Division, binary

Exponentiation, binary

Special binary operators, x can be replaced by any valid name

Modulus, binary

Integer divide, binary

Matrix product, binary

Outer product, binary

Kronecker product, binary

Matching operator, binary (in model formulae: nesting)

logical negation, NOT x

elementwise logical AND

vector logical AND

elementwise logical OR

vector logical OR

elementwise exclusive OR

Less than, binary

Greater than, binary

Equal to, binary

Greater than or equal to, binary

Less than or equal to, binary

Loads the dataset written with save

Loads specified datasets; if no arg is given it lists all available data sets

Reads a file using defaults sensible for a table/csv/delimited/fixed-width file and creates a data frame from it.

Loads add-on packages

Saves the specified objects (...) in the XDR platform-independent binary format

Saves all objects

Prints the arguments after coercing to character; sep is the character separator between arguments

Prints its arguments; generic, meaning it can have different methods for different objects

Formats an R object for pretty printing

Saves x after converting to a data frame

Output to file, until sink()

Saves a transcript of commands and/or output to a text file (TeachingDemos)

Downloads url from the net

Remote input

Useful packages: DBI interface between R and relational DBMS; RJDBC access to databases through the JDBC interface; RMySQL interface to MySQL database; RODBC ODBC database access; ROracle Oracle database interface driver; RpgSQL interface to PostgreSQL database; RSQLite SQLite interface for R

File connections of functions can also be used to read and write to the clipboard instead of a file.

Mac OS: x <‐ read.delim(pipe(“pbpaste”))

Windows: x <‐ read.delim(ʺclipboardʺ)

See also: read.clipboard (psych)

Download and install pkgs from repository (lib) or other external source

Checks for new versions and offers to install

Loads pkg, if pkg is omitted it lists packages

Removes pkg from memory

nth element

all but the nth element

first n elements

Elements from n+1 to end

specific elements

element named "name"

all elements greater than 3

all elements between 3 and 5

elements in the given set

list with elements n

nth element of the list

element named "name"

as above (w. partial matching)

element at row i, column j

row i

column j

columns 1 and 3

row named "name"

column named "name"

as above (w. partial matching)

Generic function to combine arguments with the

default forming a vector; with recursive=TRUE descends through lists combining all elements into one vector

Generates a sequence; “:” has operator priority; 1:4 + 1 is “2,3,4,5”

Generates a sequence. by= specifies increment; length= specifies desired length

Generates 1, 2, ..., length(along); useful in for loops

Replicate x times; use each to repeat “each” element of x each times; rep(c(1,2,3),2) is 1 2 3 1 2 3; rep(c(1,2,3),each=2) is 1 1 2 2 3 3

Creates a data frame of the named or unnamed arguments, e.g.: data.frame(v=1:4, ch= c("a","B","c","d"), n=10);

Shorter vectors are recycled to the length of the longest

Creates a list of the named or unnamed arguments, e.g.: list(a=c(1,2),b="hi", c=3);

Array with data x; specify dimensions like dim=c(3,4,2); elements of x recycle if x is not long enough

Matrix; elements of x recycle

factor(x,levels) encodes a vector x as a factor

Generates levels (factors) by specifying the pattern of their levels; k is the number of levels, and n is the number of replications

A data frame from all combinations of the supplied vectors or factors

as.array(x), as.character(x), as.data.frame(x), as.factor(x), as.logical(x), as.numeric(x), convert type; for a complete list, use methods(as)