Wrong encoding in R presentation - encoding

Question

I've struggling a lot with this problem since last week: I am using R presentation (.Rpres file) for the first time and it started alright, meaning that I could build a slide and visualize the result in the Presentation tab in RStudio. However, for reasons I don't understand, after a few hours of working on my presentations the Presentation tab began to show weird symbols for all the french characters in my presentation. The only way so far I could get the presentation back to showing the right characters was by playing with the "Save with encoding..." and "Reopen with encoding..." options in Rstudio.
The problem is that although this has made the french characters in the presentation look good, it is now the text in the source file (.RPres) that looks all weird (e.g. "température" instead of "température").
Here is some more details on my setup, if this can help:
> sessionInfo()
R version 3.2.3 (2015-12-10)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 7 x64 (build 7601) Service Pack 1
locale:
[1] LC_COLLATE=French_Canada.1252 LC_CTYPE=French_Canada.1252 LC_MONETARY=French_Canada.1252
[4] LC_NUMERIC=C LC_TIME=French_Canada.1252
attached base packages:
[1] graphics grDevices datasets stats utils methods base
other attached packages:
[1] readxl_0.1.1 sp_1.2-2 foreign_0.8-66 data.table_1.9.6 dplyr_0.4.3 bit64_0.9-5
[7] bit_1.1-12 RPostgres_0.1 DBI_0.3.1.9008 Rcpp_0.12.3.2
loaded via a namespace (and not attached):
[1] lattice_0.20-33 assertthat_0.1 chron_2.3-47 grid_3.2.3 R6_2.1.2 magrittr_1.5
[7] tools_3.2.3 parallel_3.2.3
I really hope someone will find a solution to this as I like this tool and would like to keep using i in the future. I was thinking of trying the revealjs package as an alternative to fix my problem but I haven't (not sure I won't have the same problem).
Thanks for your help.

Answer 1

This problem might be related to the locale specified for your computer, as explained here: https://superuser.com/questions/655273/r-locale-setting-problems-on-mac-os-x
If the result of system("locale") contains a lot of values "C", then you should try the command
system("defaults write org.R-project.R force.LANG en_US.UTF-8")
After this, you should restart R and use system("locale") to check that the locale has been updated, and hopefully you should now be able to get the correct characters the next time you compile your document.
Note: I know that this strategy has solved a similar problem for users on Linux and OS X, but I don't know if it also works if your OS is Windows.