今天看有关R书籍的时候，发现了R升级的新方法（基于我之前没有看到过这种方法说的），现将该方法与R爱好者分享。（由于我的R版本是最新的，没有办法实践），具体操作程序如下：

The first step in updating R in Windows is to open R and install the package installr if the package has not already been installed. Next, use the function library to provide access to installr. Type
at the command prompt and press enter. Then, to update R, type
at the command prompt and press enter. R will either do an update or give a message that the program is up-to-date and return False.Once installr has been installed, installr does not need to be installed again. The library must be accessed every time R is run.

来源：R quick syntax reference(page 7)