如何安装库(Readr)？

Question

我很惊讶library(readr)不能突然加载：

library(readr)
Error in loadNamespace(j <- imp[[1L]], c(lib.loc, .libPaths()), versionCheck = vI[[j]]) : 
  there is no package called ‘Rcpp’
In addition: Warning message:
package ‘readr’ was built under R version 3.2.2 
Error: package or namespace load failed for ‘readr’

所以我试着：

install.packages("Rcpp") #with all dependencies
trying URL 'https://cran.rstudio.com/bin/windows/contrib/3.2/Rcpp_0.12.1.zip'
Content type 'application/zip' length 3189720 bytes (3.0 MB)
downloaded 3.0 MB

package ‘Rcpp’ successfully unpacked and MD5 sums checked
Warning in install.packages :
cannot remove prior installation of package ‘Rcpp’

The downloaded binary packages are in
C:\Users\m\AppData\Local\Temp\RtmpMd0LfX\downloaded_packages

在那之后，我尝试了一下，就像推荐的那样：

install.packages("readr", repos=c("http://rstudio.org/_packages",   "http://cran.rstudio.com"))

also installing the dependency ‘Rcpp’

Warning in install.packages :
  cannot open: HTTP status was '404 Not Found'
Warning in install.packages :
  cannot open: HTTP status was '404 Not Found'
Warning in install.packages :
  unable to access index for repository     http://rstudio.org/_packages/bin/windows/contrib/3.2
trying URL 'http://cran.rstudio.com/bin/windows/contrib/3.2/Rcpp_0.12.1.zip'
Content type 'application/zip' length 3189720 bytes (3.0 MB)
downloaded 3.0 MB

trying URL 'http://cran.rstudio.com/bin/windows/contrib/3.2/readr_0.1.1.zip'
Content type 'application/zip' length 1128358 bytes (1.1 MB)
downloaded 1.1 MB

package ‘Rcpp’ successfully unpacked and MD5 sums checked
Warning in install.packages :
 cannot remove prior installation of package ‘Rcpp’
package ‘readr’ successfully unpacked and MD5 sums checked

The downloaded binary packages are in
C:\Users\m\AppData\Local\Temp\RtmpMd0LfX\downloaded_packages

我错过了什么吗？

Answer 1

您在Windows上，尝试更新涉及已编译代码(如readr和Rcpp)的包时会遇到一些小问题。基本上，如果加载了这些包，就不能更新它们；也没有办法卸载它们。因此，您需要在"vanilla“模式下重启R(即，只加载基础包)。在命令提示符下执行以下操作：

R --vanilla

然后，您应该能够安装这些包。我会尝试：

install.packages(c("Rcpp", "readr"))

你应该可以走了。