r-docs

name	r-docs
description	Access R package documentation and learn about packages. Use when exploring packages, finding function help, or understanding package capabilities.

R Documentation

How to discover and access R package documentation.

BTW MCP Tools (Preferred)

Always use these btw MCP tools first — they provide direct access to R documentation without running R code:

Tool	Purpose
btw_tool_docs_help_page	Get help page for a function (?pkg::fun)
btw_tool_docs_package_help_topics	List all help topics in a package
btw_tool_docs_available_vignettes	List vignettes for a package
btw_tool_docs_vignette	Read a vignette in plain text
btw_tool_docs_package_news	Read package NEWS/changelog
btw_tool_cran_search	Search for packages on CRAN
btw_tool_cran_package	Describe a CRAN package

Only fall back to R commands below if btw tools are unavailable.

Quick Reference

Task	Command
Function help	?dplyr::filter or help("filter", package = "dplyr")
Package overview	help(package = "dplyr")
List vignettes	vignette(package = "dplyr")
Open vignette	vignette("dplyr", package = "dplyr")
Search docs	help.search("linear model") or ??linear
Function args	args(dplyr::filter)
Function source	dplyr::filter (print without parens)
Package news	news(package = "dplyr")

Function Documentation

# Help for a specific function
?dplyr::filter
help("filter", package = "dplyr")

# See function arguments
args(dplyr::filter)

# See function source code
dplyr::filter
getAnywhere("filter")

# Find methods for a generic
methods("print")
methods(class = "data.frame")

Package Overview

# List all functions in a package
help(package = "dplyr")

# List exported functions
ls("package:dplyr")
getNamespaceExports("dplyr")

# Package description
packageDescription("dplyr")

# Package version
packageVersion("dplyr")

# Package dependencies
tools::package_dependencies("dplyr")

Vignettes

Vignettes are long-form documentation with examples:

# List available vignettes
vignette(package = "dplyr")
browseVignettes("dplyr")

# Open a specific vignette
vignette("dplyr", package = "dplyr")
vignette("programming", package = "dplyr")

Searching Documentation

# Search across all installed packages
help.search("linear model")
??linear

# Search for functions by name pattern
apropos("mean")
apropos("^str")  # starts with "str"

# Find which package a function belongs to
find("filter")
getAnywhere("filter")

Online Resources

pkgdown Sites

Most tidyverse and r-lib packages have pkgdown sites:

• Pattern: https://<pkg>.r-lib.org/ or https://<org>.github.io/<pkg>/
• Examples:
  • https://dplyr.tidyverse.org/
  • https://rlang.r-lib.org/
  • https://testthat.r-lib.org/

CRAN Pages

# Open CRAN page in browser
browseURL(paste0("https://cran.r-project.org/package=", "dplyr"))

CRAN pages include:

• Reference manual (PDF)
• Vignettes
• NEWS
• Dependencies
• Reverse dependencies

GitHub/GitLab

Find source code and issues:

# Package URL (if set in DESCRIPTION)
packageDescription("dplyr")$URL
packageDescription("dplyr")$BugReports

Exploring Package Contents

# List datasets in a package
data(package = "ggplot2")

# Load a dataset
data("mpg", package = "ggplot2")

# List all objects (including internal)
ls(getNamespace("dplyr"))

# Check if function is exported
"filter" %in% getNamespaceExports("dplyr")

Understanding Function Behavior

# See default argument values
formals(dplyr::filter)

# Check if function is S3 generic
pryr::is_s3_generic("print")
sloop::is_s3_generic("print")

# Find S3 method for a class
getS3method("print", "data.frame")
sloop::s3_dispatch(print(mtcars))

# See all methods for a generic
methods("print")
sloop::s3_methods_generic("print")

Useful Packages for Exploration

Package	Purpose
sloop	Understand S3/S4 OOP
pryr	Inspect R internals
lobstr	Visualize data structures
pkgapi	Extract package API

Anti-patterns

• Installing packages without user approval - always ask before running install.packages()
• Using library() just to access help (use ?pkg::fun instead)
• Ignoring vignettes (they often have the best explanations)
• Not checking examples in help pages
• Searching the web before checking built-in docs

References

• R Documentation
• rdrr.io - searchable R documentation
• CRAN Task Views - packages by topic