dmap {purrr} | R Documentation |
dmap()
is just like map()
but always returns a
data frame. In addition, it handles grouped or sliced data frames.
dmap(.d, .f, ...) dmap_at(.d, .at, .f, ...) dmap_if(.d, .p, .f, ...)
.d |
A data frame. |
.f |
A function, formula, or atomic vector. If a function, it is used as is. If a formula, e.g. If character or integer vector, e.g. |
... |
Additional arguments passed on to |
.at |
A character vector of names or a numeric vector of
positions. Only those elements corresponding to |
.p |
A single predicate function, a formula describing such a
predicate function, or a logical vector of the same length as |
dmap_at()
and dmap_if()
recycle length 1 vectors to
the group sizes.
# dmap() always returns a data frame: dmap(mtcars, summary) # dmap() also supports sliced data frames: sliced_df <- mtcars[1:5] %>% slice_rows("cyl") sliced_df %>% dmap(mean) sliced_df %>% dmap(~ .x / max(.x)) # This is equivalent to the combination of by_slice() and dmap() # with 'rows' collation of results: sliced_df %>% by_slice(dmap, mean, .collate = "rows")