Finished installing R and Rstudio, we come to the installation of Rtools. (Please check the tutorial vedio in coursera) It seems all went fine before installing devtools. However, typing
>install.packages("devtools")
really took a long time to download a series of packages. When finished, a pop-up info indicated an error: “https://class.coursera.org/datascitoolbox-031/lecture/55”
google it, and we found this would work:
Sys.setlocale('LC_ALL','C')
Reasons are complex, here post the reference: http://cos.name/cn/topic/157794/