我是一个R新手  我在调用一个包的时候 出现了这样的提示：
> library(CPE)
Loading required package: survival
Loading required package: rms
Loading required package: Hmisc
Loading required package: lattice
Loading required package: Formula
Loading required package: ggplot2
Find out what's changed in ggplot2 at
http://github.com/hadley/ggplot2/releases.

Attaching package: ‘Hmisc’

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

    format.pval, round.POSIXt, trunc.POSIXt, units

Loading required package: SparseM

Attaching package: ‘SparseM’

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

    backsolve

上边的提示  说是我要下载

Loading required package: survival
Loading required package: rms
Loading required package: Hmisc
Loading required package: lattice
Loading required package: Formula
Loading required package: ggplot2
Find out what's changed in ggplot2 at
http://github.com/hadley/ggplot2/releases.

这些包  可是我下载了以后 再次调用
> library(CPE) 还是提示以上这些
哪位好心的朋友能帮帮我  这是怎么回事吗？