3.5.1版本这是什么错误?
Warning in install.packages :
unable to access index for repository https://cran.rstudio.com/src/contrib:
cannot open URL 'https://cran.rstudio.com/src/contrib/PACKAGES'
Installing package into ‘C:/Users/Andminstrator/Documents/R/win-library/3.5’
(as ‘lib’ is unspecified)
Warning in install.packages :
unable to access index for repository https://cran.rstudio.com/src/contrib:
cannot open URL 'https://cran.rstudio.com/src/contrib/PACKAGES'
Warning in install.packages :
package ‘cerat’ is not available (for R version 3.5.1)
Warning in install.packages :
unable to access index for repository https://cran.rstudio.com/bin/windows/contrib/3.5:
cannot open URL 'https://cran.rstudio.com/bin/windows/contrib/3.5/PACKAGES'
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