먼저 dplyr와 ggplot2 패키지 설치
library(dplyr)
##
## 다음의 패키지를 부착합니다: 'dplyr'
## The following objects are masked from 'package:stats':
##
## filter, lag
## The following objects are masked from 'package:base':
##
## intersect, setdiff, setequal, union
library(ggplot2)
ggplot(iris, aes(x= Sepal.Length, y= Sepal.Width))+
geom_point()