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apropos: Find Objects by (Partial) Name

apropos

R Documentation

Find Objects by (Partial) Name

Description

apropos() returns a character vector giving the names of objects in the search list matching (as a regular expression) what.

find() returns where objects of a given name can be found.

Usage

apropos(what, where = FALSE, ignore.case = TRUE, mode = "any")

find(what, mode = "any", numeric = FALSE, simple.words = TRUE)

Arguments

`what`	character string. For `simple.words = FALSE` the name of an object; otherwise a regular expression to match object names against.
`where, numeric`	a logical indicating whether positions in the search list should also be returned
`ignore.case`	logical indicating if the search should be case-insensitive, `TRUE` by default.
`mode`	character; if not `"any"`, only objects whose `mode` equals `mode` are searched.
`simple.words`	logical; if `TRUE`, the `what` argument is only searched as a whole word.

Details

If mode != "any" only those objects which are of mode mode are considered.

find is a different user interface for a similar task to apropos. By default (simple.words == TRUE), only whole names are matched. Unlike apropos, matching is always case-sensitive.

Unlike the default behaviour of ls, names which begin with a . are included (and these are often ‘internal’ objects — as from R 3.4.0 most such are excluded).

Value

For apropos, a character vector sorted by name. For where = TRUE this has names giving the (numerical) positions on the search path.

For find, either a character vector of environment names or (for numeric = TRUE) a numerical vector of positions on the search path with names the names of the corresponding environments.

Author(s)

Originally, Kurt Hornik and Martin Maechler (May 1997).

Examples

require(stats)


## Not run: apropos("lm")
apropos("GLM")                      # several
apropos("GLM", ignore.case = FALSE) # not one
apropos("lq")

cor <- 1:pi
find("cor")                         #> ".GlobalEnv"   "package:stats"
find("cor", numeric = TRUE)                     # numbers with these names
find("cor", numeric = TRUE, mode = "function")  # only the second one
rm(cor)

## Not run: apropos(".", mode="list")  # a long list

# need a DOUBLE backslash '\\' (in case you don't see it anymore)
apropos("\\[")

# everything % not diff-able
length(apropos("."))

# those starting with 'pr'
apropos("^pr")

# the 1-letter things
apropos("^.$")
# the 1-2-letter things
apropos("^..?$")
# the 2-to-4 letter things
apropos("^.{2,4}$")

# the 8-and-more letter things
apropos("^.{8,}$")
table(nchar(apropos("^.{8,}$")))