R:summarise_all,summarise_each,summarise_each_,summarise_at

Peter Lin

2018/4/6

library(dplyr)
library(purrr)

mtcars %>% map_dbl(mean)

##        mpg        cyl       disp         hp       drat         wt 
##  20.090625   6.187500 230.721875 146.687500   3.596563   3.217250 
##       qsec         vs         am       gear       carb 
##  17.848750   0.437500   0.406250   3.687500   2.812500

mtcars %>% summarise_all(mean)

##        mpg    cyl     disp       hp     drat      wt     qsec     vs
## 1 20.09062 6.1875 230.7219 146.6875 3.596563 3.21725 17.84875 0.4375
##        am   gear   carb
## 1 0.40625 3.6875 2.8125

mtcars %>% summarise_each(funs(mean))

##        mpg    cyl     disp       hp     drat      wt     qsec     vs
## 1 20.09062 6.1875 230.7219 146.6875 3.596563 3.21725 17.84875 0.4375
##        am   gear   carb
## 1 0.40625 3.6875 2.8125

mtcars %>% summarise_at(1:11,funs(mean))

##        mpg    cyl     disp       hp     drat      wt     qsec     vs
## 1 20.09062 6.1875 230.7219 146.6875 3.596563 3.21725 17.84875 0.4375
##        am   gear   carb
## 1 0.40625 3.6875 2.8125

mtcars %>% summarise_at(vars('disp','cyl'),funs(mean))

##       disp    cyl
## 1 230.7219 6.1875

mtcars %>% summarise_at(vars(disp,am,cyl),funs(mean))

##       disp      am    cyl
## 1 230.7219 0.40625 6.1875

mtcars %>% summarise_each(funs(mean),disp,cyl,am)

##       disp    cyl      am
## 1 230.7219 6.1875 0.40625

mtcars %>% summarise_each_(funs(mean),vars(disp,cyl,am))

##       disp    cyl      am
## 1 230.7219 6.1875 0.40625

mtcars %>% summarise_each(funs(mean),1:3)

##        mpg    cyl     disp
## 1 20.09062 6.1875 230.7219

mtcars %>% summarise_each_(funs(mean),1:3)

##        mpg    cyl     disp
## 1 20.09062 6.1875 230.7219

mtcars %>% summarise_each_(funs(mean),c('disp','cyl','am'))

##       disp    cyl      am
## 1 230.7219 6.1875 0.40625