apropos
Find Objects by (Partial) Name
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.
- Keywords
- data, environment, documentation
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 = FALSEthe 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,
TRUEby default.- mode
character; if not
"any", only objects whosemodeequalsmodeare searched.- simple.words
logical; if
TRUE, thewhatargument 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.
See Also
glob2rx to convert wildcard patterns to regular expressions.
objects for listing objects from one place,
help.search for searching the help system,
search for the search path.
Examples
library(utils)
# NOT RUN {
require(stats)
# }
# NOT RUN {
<!-- %% some of these have enormous output that varies a lot by version -->
# }
# NOT RUN {
apropos("lm")
# }
# NOT RUN {
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
# }
# NOT RUN {
# need a DOUBLE backslash '\\' (in case you don't see it anymore)
apropos("\\[")
# }
# NOT RUN {
# 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,}$")))
# }