[NTG-context] Filter module for R

[Aditya Mahajan]

On Mon, 15 Jun 2020, Aditya Mahajan wrote:

> On Sun, 14 Jun 2020, Fabrice L wrote:
>
>> Hi,
>> 
>> Following a question about the broken R module (R the statistical 
>> software), Aditya suggested me the filter module (thanks to him). I’m about 
>> to distribute a set of course notes to colleagues, and I need to deal with 
>> details now. I have one problem and two questions.
>> 
>> 1) the filter collect R code between \startR / \stopR and submit this code 
>> to R. As it can be seen in the following minimal example, when a label 
>> contains an accented character (« Fréquence » in my example), the pdf 
>> graphic does not contains the « é ». Strangely, the snippet of code (which 
>> is saved locally as « test2-temp-R-0.tmp » (for test2.tex)) when submitted 
>> with the same command as the filtercommand, works correctly; that means the 
>> same file works when submitted to R outside of ConTeXt. I have no idea how 
>> to solve this.
>
> Are you running the exact same command as the `filtercommand`. If so, I don't 
> know why running the `filtercommand` through context vs directly typing it on 
> the terminal should behave differently. The filter module effectively just 
> runs os.execute("filtercommand"). I don't use R so I am unable to debug 
> further.

I can reproduce this output side the filter module. If I directly run os.execute(...) from a lua session, the output is correct but running it through context gives the wrong output. I am guessing this is something to do with locale. I notice that the output of os.execute("locale") from context is different from that from my shell. But I don't know why locale should affect UTF characters in R. Perhaps someone with more knowledge of R can comment on that.

\starttext

\startluacode
   lfs.mkdir("output/")
\stopluacode

\startbuffer[code]
    pdf("output/MyHistogram.pdf",5,5)
    X <- rnorm(200,mean=10,sd=2)
    hist(X, col =  "red3" ,  xlab="Score QI" , main="", ylab="fréquence")
\stopbuffer

\savebuffer[prefix=no, list=code, file={output/code.r}]

\startluacode
   print(">>>>", "RUNNING R CMD")
   os.execute("R CMD BATCH --no-timing --save --restore output/code.r output/out")
\stopluacode

\externalfigure[RPlots/MyHistogram.pdf][width=.5\textwidth]

\stoptext

Aditya