map
-like functions, similar to the ones implemented in purrr:
map()
returns the results of .f
applied to .x
as list.
If .f
is not a function, map
will call [[
on all elements of .x
using the value of .f
as index.
imap()
applies .f
to each value of .x
(passed as first argument) and its name (passed as second argument).
If .x
does not have names, a sequence along .x
is passed as second argument instead.
pmap()
expects .x
to be a list of vectors of equal length, and then applies .f
to the first element of
each vector of .x
, then the second element of .x
, and so on.
map_if()
applies .f
to each element of .x
where the predicate .p
evaluates to TRUE
.
map_at()
applies .f
to each element of .x
referenced by .at
. All other elements remain unchanged.
keep()
keeps those elements of .x
where predicate .p
evaluates to TRUE
.
discard()
discards those elements of .x
where predicate .p
evaluates to TRUE
.
every()
is TRUE
if predicate .p
evaluates to TRUE
for each .x
.
some()
is TRUE
if predicate .p
evaluates to TRUE
for at least one .x
.
detect()
returns the first element where predicate .p
evaluates to TRUE
.
walk()
, iwalk()
and pwalk()
are the counterparts to map()
, imap()
and pmap()
, but
just visit (or change by reference) the elements of .x
. They return input .x
invisibly.
Additionally, the functions map()
, imap()
and pmap()
have type-safe variants with the following suffixes:
*_lgl()
returns a logical(length(.x))
.
*_int()
returns a integer(length(.x))
.
*_dbl()
returns a double(length(.x))
.
*_chr()
returns a character(length(.x))
.
*_br()
returns an object where the results of .f
are put together with base::rbind()
.
*_bc()
returns an object where the results of .f
are put together with base::cbind()
.
*_dtr()
returns a data.table::data.table()
where the results of .f
are put together
in an base::rbind()
fashion.
*_dtc()
returns a data.table::data.table()
where the results of .f
are put
together in an base::cbind()
fashion.
map(.x, .f, ...)map_lgl(.x, .f, ...)
map_int(.x, .f, ...)
map_dbl(.x, .f, ...)
map_chr(.x, .f, ...)
map_br(.x, .f, ...)
map_bc(.x, .f, ...)
map_dtr(.x, .f, ..., .fill = FALSE, .idcol = NULL)
map_dtc(.x, .f, ...)
pmap(.x, .f, ...)
pmap_lgl(.x, .f, ...)
pmap_int(.x, .f, ...)
pmap_dbl(.x, .f, ...)
pmap_chr(.x, .f, ...)
pmap_dtr(.x, .f, ..., .fill = FALSE, .idcol = NULL)
pmap_dtc(.x, .f, ...)
imap(.x, .f, ...)
imap_lgl(.x, .f, ...)
imap_int(.x, .f, ...)
imap_dbl(.x, .f, ...)
imap_chr(.x, .f, ...)
imap_dtr(.x, .f, ..., .fill = FALSE, .idcol = NULL)
imap_dtc(.x, .f, ...)
keep(.x, .f, ...)
discard(.x, .p, ...)
map_if(.x, .p, .f, ...)
# S3 method for default
map_if(.x, .p, .f, ...)
map_at(.x, .at, .f, ...)
every(.x, .p, ...)
some(.x, .p, ...)
detect(.x, .p, ...)
walk(.x, .f, ...)
iwalk(.x, .f, ...)
pwalk(.x, .f, ...)
(function()
| character()
| integer()
)
Function to apply, or element to extract by name (if .f
is character()
) or position (if .f
is integer()
).
(any
)
Additional arguments passed down to .f
or .p
.
(logical(1)
)
Passed down to data.table::rbindlist()
.
(logical(1)
)
Passed down to data.table::rbindlist()
.
(function()
| logical()
)
Predicate function.
(character()
| integer()
| logical()
)
Index vector.