安装包xlsx在R中不起作用

Question

我一直在尝试在R中安装“xlsx”软件包。第一次尝试这样做时，R给了我错误：

package ‘xlsx’ is available as a source package but not as a binary

Warning in install.packages :
  package ‘xlsx’ is not available (as a binary package for R version 3.1.3) 

之后，我尝试使用命令install.packages("xlsx",type="source")安装软件包。然后看起来包装已成功安装：

 * installing *source* package 'xlsx' ...
    ** package 'xlsx' successfully unpacked and MD5 sums checked
    ** R
    ** inst
    ** preparing package for lazy loading
    ** help
    *** installing help indices
    ** building package indices
    ** installing vignettes
    ** testing if installed package can be loaded
    *** arch - i386
    *** arch - x64
    * DONE (xlsx)

The downloaded source packages are in
    ‘C:\Users\zahra\AppData\Local\Temp\RtmpszYeze\downloaded_packages’

但是当我尝试执行read.xlsx命令时，R仍然给出了错误：

Error: could not find function "read.xlsx"

如果有人告诉我我做错了什么，我真的很感激。

提前致谢。