Is there a set of best practices or documentation for working with Unicode in knitr and Rmarkdown? I can't seem to get any glyphs to show up properly when knitting a document.
For example, this works in the console (in Rstudio):
> cat("\U2660 \U2665 \U2666 \U2663")
♠ ♥ ♦ ♣
But when knitting I get this:
It looks like an encoding issue specific to Windows, and may be related to this issue: https://github.com/hadley/evaluate/issues/59 Unfortunately we have to wait for a fix in base R, but if you don't have to use cat(), and this expression is a top-level expression in your code chunk (e.g. not inside a for-loop or if-statement), I guess this may work:
knitr::asis_output("\U2660 \U2665 \U2666 \U2663")
It passes the character string directly to knitr and bypasses cat(), since knitr cannot reliably catch multibyte characters written out by cat() on Windows -- it depends on whether the characters can be represented by your system's native encoding.
For anyone else who came across this after trying to get emoji support in Rstudio/Rmarkdown documents, another possible issue is that if the file encoding isn't set to UTF-8, the resulting compiled document won't support emojis either.
In order for emoji to work in Rmarkdown, you must change the file encoding of the Rmd document. Go to File -> Reopen with encoding, then select UTF-8.
Once you have ensured the file is open in UTF-8 encoding, you should be able to compile with emoji support.
You should even be able to paste emoji from a browser directly into the document.
It is probably a good idea to change the default encoding for all files to UTF-8 so that you don't have to deal with this issue again.
Phew, that was close `r knitr::asis_output("\U1F605 \U2660 \U2665 \U2666 \U2663")`
```{r, echo=FALSE}
knitr::asis_output("Phew, that was close \U1F605 \U2660 \U2665 \U2666 \U2663")
```
Unfortunately, this package isn't yet on CRAN, but it can be installed with devtools::install_github("hadley/emo")
emo::ji("face")
There are some more examples here
