How to show foreign characters in ggplot output in RMarkdown?

Question

I am currently working on a paper with ggplot plots which includes Turkish characters in labels. When I knit this RMarkdown file, Turkish characters such as "ğ" and "ı" are seen as "." in the plots.

ggplot(cars,aes(x = speed, y = dist))+
  geom_point()+
   labs(x = "Hız")

when I knit this chunk there is a warning ## Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, :## conversion failure on ’Hız’ in ’mbcsToSbcs’: dot substituted for <b1> and the output is .

I tried to put the HTML codes of the characters in to labels but it also didn't work.

How can I fix this issue?

Answer 1

The simpliest way using ggsave and \includegraphics. (PDF output)

---
title: "rmd2023"
output:
  pdf_document: 
    latex_engine: xelatex      
date: '2023-04-11'
---       

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
library(tidyverse)
```

```{r cars, include=F, warning=F}
ggplot(cars,aes(x = speed, y = dist))+
  geom_point() +
   labs(x = "H\u0131z") 

ggsave("Turk.png", dpi = 300)
```

\includegraphics{Turk.png}