R (programming language): Difference between revisions

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| file_ext = {{Unbulleted list|.r<ref>{{Cite web|title=R scripts|url=http://mercury.webster.edu/aleshunas/R_learning_infrastructure/R%20scripts.html|access-date=2021-07-17|website=mercury.webster.edu}}</ref>|.rdata|.rhistory|.rds|.rda<ref>{{Cite web|date=2017-06-09|title=R Data Format Family (.rdata, .rda)|url=https://www.loc.gov/preservation/digital/formats/fdd/fdd000470.shtml|access-date=2021-07-17|website=Loc.gov}}</ref>}}

}}

{{redirect-distinguish|R lang|Erlang}}

'''R''' is a [[programming language]] for [[statistical computing]] and [[Data and information visualization|data visualization]]. It has been widely adopted in the fields of [[data mining]], [[bioinformatics]], [[data analysis]], and [[data science]].<ref>{{Cite journal

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== History ==

{{Multiple image |total_width = 250 | align = left

{{Gallery

|title header = Co-originators of the R language

|File: image1 = Ross Ihaka (5189180796).jpg

|width=160 | height=170 |noborder=yes

| caption1 = [[Ross Ihaka]]

|align=center

|File: image2 = Robert Gentleman on R Consortium.jpg

|footer=

| caption2 = [[Robert Gentleman (statistician)|Robert Gentleman]]

|File:Ross Ihaka (5189180796).jpg

|Ross Ihaka

|alt1=

|File:Robert Gentleman on R Consortium.jpg

|Robert Gentleman

|alt2=

}}

R was started by professors [[Ross Ihaka]] and [[Robert Gentleman (statistician)|Robert Gentleman]] as a programming language to teach introductory statistics at the [[University of Auckland]].<ref name="otago_pg12">{{Cite web

|last=Ihaka

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</syntaxhighlight>

AnotherAn alternative to nested functions is the use of intermediate objects, rather than the pipe operator:

<syntaxhighlight lang="rout">

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> print(num_mtcars_subset)

[1] 11

</syntaxhighlight>While the pipe operator can produce code that is easier to read, itinfluential isR advisableprogrammers like [[Hadley Wickham]] suggest to chain together at most 10-15 lines of code using this operator, asand wellsaving as to chunk codethem into [[Taskobjects (projecthaving management)|sub-tasks]]meaningful thatnames areto savedavoid into[[Code objectsobfuscating|code having meaningful namesobfuscation]].<ref>{{Cite book |last=Wickham |first=Hadley |url=https://r4ds.hadley.nz/ |title=R for data science: import, tidy, transform, visualize, and model data |last2=Çetinkaya-Rundel |first2=Mine |last3=Grolemund |first3=Garrett |date=2023 |publisher=O'Reilly |isbn=978-1-4920-9740-2 |edition=2nd |___location=Beijing; Sebastopol, CA |chapter=4 Workflow: code style |oclc=on1390607935 |chapter-url=https://r4ds.hadley.nz/workflow-style.html}}</ref>

The following is an example having fewer than 10 lines, which some readers may find difficult to grasp in the absence of intermediate named steps:<syntaxhighlight lang="r" line="1">(\(x, n = 42, key = c(letters, LETTERS, " ", ":", ")"))

strsplit(x, "")[[1]] |>

(Vectorize(\(chr) which(chr == key) - 1))() |>

(`+`)(n) |>

(`%%`)(length(key)) |>

(\(i) key[i + 1])() |>

paste(collapse = "")

)("duvFkvFksnvEyLkHAErnqnoyr")</syntaxhighlight>The following is a version of the preceding code that is easier to read:<syntaxhighlight lang="r">

default_key <- c(letters, LETTERS, " ", ":", ")")

f <- function(x, n = 42, key = default_key) {

split_input <- strsplit(x, "")[[1]]

results <- (Vectorize(\(chr) which(chr == key) - 1))(split_input) |>

(`+`)(n) |>

(`%%`)(length(key)) |>

(\(i) key[i + 1])()

combined_results <- paste(results, collapse = "")

return(combined_results)

}

f("duvFkvFksnvEyLkHAErnqnoyr")

</syntaxhighlight>

=== Object-oriented programming ===

The R language has native support for [[object-oriented programming]]. There are two native [[Application framework|frameworks]], the so-called S3 and S4 systems. The former, being more informal, supports single dispatch on the first argument, and objects are assigned to a class simply by setting a "class" attribute in each object. The latter is a system like the [[CLOS|Common Lisp Object System (CLOS)]], with formal classes (also derived from [[S (programming language)#S4|S]]) and generic methods, which supports [[multiple dispatch]] and [[multiple inheritance]]<ref>{{cite web|url=https://stat.ethz.ch/R-manual/R-devel/library/base/html/UseMethod.html|title=Class Methods|access-date=2024-04-25}}</ref>