dplyr はデータ処理を簡潔に書けて便利。しかし、Rscript でバッチ処理ときなど、毎回警告がでるのはうっとうしい。
> library(dplyr)
Attaching package: 'dplyr'
The following object is masked from 'package:stats':
filter
The following objects are masked from 'package:base':
intersect, setdiff, setequal, union
warn.conflicts=FALSE でOK。
library(dplyr, warn.conflicts=F)