| Rdutils {tools} | R Documentation |
Utilities for computing on the information in Rd objects.
Rd_db(package, dir, lib.loc = NULL)
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. |
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.
Rd_db is still experimental. Names, interface and value might
change in future versions.
## 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))