Rscript does not load methods package, R does — why, and what are the consequences?

问题

Just saw this:

$ Rscript -e \"sessionInfo()[\'basePkgs\']\"
$basePkgs
[1] \"stats\"     \"graphics\"  \"grDevices\" \"utils\"     \"datasets\"  \"base\"

$ R --vanilla --slave -e \"sessionInfo()[\'basePkgs\']\"
$basePkgs
[1] \"stats\"     \"graphics\"  \"grDevices\" \"utils\"     \"datasets\"  \"methods\"
[7] \"base\"

The methods package seems to be always available when running R, but not with Rscript. I suspect that this is to gain performance, but are there any practical implications besides the obvious? I\'m asking because of a funny bug that is triggered by the presence or absence of the methods package.

回答1:

According to ?Rscript the methods package isn't loaded because, "The default for Rscript omits methods as it takes about 60% of the startup time."

来源：https://stackoverflow.com/questions/19680462/rscript-does-not-load-methods-package-r-does-why-and-what-are-the-consequen