Warning in install.packages :

  downloaded length 1093632 != reported length 4020700

package ‘isoband’ successfully unpacked and MD5 sums checked

Warning in install.packages :

  从zip文件中抽取1时出了错

Warning in install.packages :

  无法打开压缩文件'ggplot2/DESCRIPTION'，可能是因为'No such file or directory'

Error in install.packages : 无法打开链结