Difference between revisions of "List of R functions"
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== Flow and control and function definition == | == Flow and control and function definition == | ||
+ | |||
+ | {|{{prettytable}} | ||
+ | |+ '''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 == | ||
+ | |||
+ | {|{{prettytable}} | ||
+ | |+ '''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 == | ||
+ | |||
+ | {|{{prettytable}} | ||
+ | |+ '''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'' | ||
+ | |} | ||
== Statistical tests == | == Statistical tests == |
Revision as of 07:06, 5 May 2011
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This page contains listings of some R functions and commands by category.
Contents
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 |
Statistical tests
function name | functionality |
---|---|
t.test | en:Student's t-test |
aov | en:Analysis of variance |