查看包版本

条件：应至少安装包装。如果未在当前会话中加载，则不成问题。

  ## Checking package version which was installed at past or 
  ## installed currently but not loaded in the current session

  packageVersion("seqinr")
  # [1] ‘3.3.3’
  packageVersion("RWeka")
  # [1] ‘0.4.29’