r - 为什么 .Rprofile 中的 library("dplyr") 行为不同

Question

我很困惑为什么 .Rprofile 中的语句与常规代码有如此不同的效果。具体来说，我想包含library("dplyr")在 .Rprofile 中以使其始终加载到 OSX 中。

一个.Rprofile的效果如下：

library("lubridate")
library("dplyr")

是：

Attaching package: ‘dplyr’

The following objects are masked from ‘package:lubridate’:

    intersect, setdiff, union

The following objects are masked from ‘package:base’:

    intersect, setdiff, setequal, union

如果 .Rprofile 只有，则作为 R 会话中的第一条语句library("lubridate")的效果是：library("dplyr")

Attaching package: ‘dplyr’

The following object is masked from ‘package:stats’:

    filter

The following objects are masked from ‘package:lubridate’:

    intersect, setdiff, union

The following objects are masked from ‘package:base’:

    intersect, setdiff, setequal, union

结果 dplyr 之类的命令filter无法正常工作。为什么是这样？