我先是输入install.package("AER"),出现Warning in install.packages :  InternetOpenUrl failed: '无法解析服务器的名称或地址
接着手动下载程序包，手动安装还是装不上，Installing package into ‘C:/Users/li/Documents/R/win-library/3.1’
(as ‘lib’ is unspecified)
Warning in install.packages :
  cannot open compressed file 'AER_1.2-4安装包/DESCRIPTION', probable reason 'No such file or directory'
Error in install.packages : cannot open the connection
这是咋回事？哪位大 神帮忙解决下，不胜感激。。。。还有linstall to library 路径怎么改呢？我用的是Rstudio