在 R 中工作时，分离所有的包。

在解决另一个问题的过程中，我遇到了这个问题:

我可以通过以下方式删除所有 R 对象：

rm(list = ls(all = TRUE))

有没有相应的命令可以在工作会话期间分离已安装的软件包？

> sessionInfo()
R version 2.12.2 (2011-02-25)
Platform: i386-pc-mingw32/i386 (32-bit)

locale:
[1] LC_COLLATE=English_United States.1252 
[2] LC_CTYPE=English_United States.1252   
[3] LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                          
[5] LC_TIME=English_United States.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base 

需要使用ggplot2库

Loading required package: ggplot2
Loading required package: reshape
Loading required package: plyr

Attaching package: 'reshape'

The following object(s) are masked from 'package:plyr':

    round_any

Loading required package: grid
Loading required package: proto

sessionInfo()

R version 2.12.2 (2011-02-25)
Platform: i386-pc-mingw32/i386 (32-bit)

locale:
[1] LC_COLLATE=English_United States.1252 
[2] LC_CTYPE=English_United States.1252   
[3] LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                          
[5] LC_TIME=English_United States.1252    

attached base packages:
[1] grid      stats     graphics  grDevices utils     datasets  methods  
[8] base     

other attached packages:
[1] ggplot2_0.8.9 proto_0.3-9.1 reshape_0.8.4 plyr_1.4 

我尝试过这种方法，虽然它不是全局解决方案，但仍有效：

pkg <- c("package:ggplot2_0.8.9", "package:proto_0.3-9.1", "package:reshape_0.8.4",  "package:plyr_1.4")

 detach(pkg, character.only = TRUE)

Error in detach(pkg, character.only = TRUE) : invalid 'name' argument
In addition: Warning message:
In if (is.na(pos)) stop("invalid 'name' argument") :
  the condition has length > 1 and only the first element will be used

我需要的是类似于全局的东西:

  rm(list = ls(all = TRUE))

针对对象，预期不会删除附加的基础包

谢谢；