summarise {dplyr} | R Documentation |
Summarise multiple values to a single value.
summarise(.data, ...) summarise_(.data, ..., .dots) summarize(.data, ...) summarize_(.data, ..., .dots)
.data |
A tbl. All main verbs are S3 generics and provide methods
for |
... |
Name-value pairs of summary functions like |
.dots |
Used to work around non-standard evaluation. See
|
An object of the same class as .data
. One grouping level will
be dropped.
Data frame row names are silently dropped. To preserve, convert to an explicit variable.
Data frames are the only backend that supports creating a variable and using it in the same summary. See examples for more details.
Other single.table.verbs: arrange
,
filter
, mutate
,
select
, slice
summarise(mtcars, mean(disp)) summarise(group_by(mtcars, cyl), mean(disp)) summarise(group_by(mtcars, cyl), m = mean(disp), sd = sd(disp)) # With data frames, you can create and immediately use summaries by_cyl <- mtcars %>% group_by(cyl) by_cyl %>% summarise(a = n(), b = a + 1) ## Not run: # You can't with data tables or databases by_cyl_dt <- mtcars %>% dtplyr::tbl_dt() %>% group_by(cyl) by_cyl_dt %>% summarise(a = n(), b = a + 1) by_cyl_db <- src_sqlite(":memory:", create = TRUE) %>% copy_to(mtcars) %>% group_by(cyl) by_cyl_db %>% summarise(a = n(), b = a + 1) ## End(Not run)