Summarise multiple values to a single value.

Summarise multiple values to a single value.

summarise(.data, ...)

summarise_(.data, ..., .dots)

summarize(.data, ...)

summarize_(.data, ..., .dots)

A tbl. All main verbs are S3 generics and provide methods for tbl_df, tbl_dt and tbl_sql.
Name-value pairs of summary functions like min(), mean(), max() etc.
Used to work around non-standard evaluation. See vignette("nse") for details.

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.

Backend variations

Data frames are the only backend that supports creating a variable and using it in the same summary. See examples for more details. you create

See Also

Other single.table.verbs: arrange, arrange_; filter, filter_; mutate, mutate_, transmute, transmute_; rename, rename_, select, select_; slice, slice_

  • summarise
  • summarise_
  • summarize
  • summarize_
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 %>% 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)
## ---------------------------------------------
Documentation reproduced from package dplyr, version, License: MIT + file LICENSE

Community examples at Sep 3, 2019 dplyr v0.7.8

mtcars %>% group_by(gear) %>% summarise(cor = cor(mpg, hp))

cielo_azzuro at Aug 4, 2019 dplyr v0.7.8

summarize(titanic, mean = mean(Age, na.rm=TRUE), sd = sd(Age, na.rm=TRUE)) The command above will generate a summary that includes the mean and standard deviation of the age of passengers in the freely-available Titanic data set. The argument na.rm=True ensures that empty cells are not included in the mean() and sd() calculations.