split.R

library(dplyr)

## 
## Attaching package: 'dplyr'

## The following objects are masked from 'package:stats':
## 
##     filter, lag

## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union

# Number of Group
numberOfGroup <- 5
iris$group <-
    rep(1:numberOfGroup, each = nrow(iris) %/% numberOfGroup)
head(iris)

##   Sepal.Length Sepal.Width Petal.Length Petal.Width Species group
## 1          5.1         3.5          1.4         0.2  setosa     1
## 2          4.9         3.0          1.4         0.2  setosa     1
## 3          4.7         3.2          1.3         0.2  setosa     1
## 4          4.6         3.1          1.5         0.2  setosa     1
## 5          5.0         3.6          1.4         0.2  setosa     1
## 6          5.4         3.9          1.7         0.4  setosa     1

iris %>% group_by(group) %>% summarise(mean = mean(Petal.Width), n = n())

## # A tibble: 5 x 3
##   group      mean     n
##   <int>     <dbl> <int>
## 1     1 0.2466667    30
## 2     2 0.6233333    30
## 3     3 1.3400000    30
## 4     4 1.7733333    30
## 5     5 2.0133333    30