R: Rd Utilities

Rdutils {tools} | R Documentation

## Rd Utilities

### Description

Utilities for computing on the information in Rd objects.

### Usage

    Rd_db(package, dir, lib.loc = NULL)

### Arguments

`package` | a character string naming an installed package.
`dir` | a character string specifying the path to a package's root source directory. This should contain the subdirectory ‘man’ with R documentation sources (in Rd format). Only used if `package` is not given.
`lib.loc` | a character vector of directory names of R libraries, or `NULL`. The default value of `NULL` corresponds to all libraries currently known. The specified library trees are used to search for `package`.

### Details

`Rd_db` builds a simple database of all Rd objects in a package, as a list of the results of running `parse_Rd` on the Rd source files in the package and processing platform conditionals.

### See Also

`parse_Rd`

### Examples

    ## Build the Rd db for the (installed) base package.
    db <- Rd_db("base")

    ## Keyword metadata per Rd object.
    keywords <- lapply(db, tools:::.Rd_get_metadata, "keyword")
    ## Tabulate the keyword entries.
    kw_table <- sort(table(unlist(keywords)))
    ## The 5 most frequent ones:
    rev(kw_table)[1 : 5]
    ## The "most informative" ones:
    kw_table[kw_table == 1]

    ## Concept metadata per Rd file.
    concepts <- lapply(db, tools:::.Rd_get_metadata, "concept")
    ## How many files already have \concept metadata?
    sum(sapply(concepts, length) > 0)
    ## How many concept entries altogether?
    length(unlist(concepts))

[Package tools version 3.5.1 Index]