windows - R Markdown v2 到 pdf。绘图中出现非拉丁字符时出现转换错误

Question

图中的非英文字符无法正确显示。这是一个可重现的例子。

---
title: "Untitled"
output:
  pdf_document:
    latex_engine: xelatex
  html_document:
    highlight: tango
    theme: null
---

This is an R Markdown document. Markdown is a simple formatting syntax for authoring HTML, PDF, and MS Word documents. For more details on using R Markdown see <http://rmarkdown.rstudio.com>.

When you click the **Knit** button a document will be generated that includes both content as well as the output of any embedded R code chunks within the document. You can embed an R code chunk like this:

```{r}
summary(cars)
```

You can also embed plots, for example:

```{r, echo=FALSE}
plot(cars, main="Τίτλος στα ελληνικά")
```

在 pdf 中编织会在绘图之前产生如下几行(当然可以使用 warning = FALSE 省略)，它不显示非英文标题。

## Warning: conversion failure on 'Ξ¤ΞτλΞΟ‚ στα ελληνΞΞΞ¬' in 'mbcsToSbcs': dot substituted for <ce>
## Warning: conversion failure on 'Ξ¤ΞτλΞΟ‚ στα ελληνΞΞΞ¬' in 'mbcsToSbcs': dot substituted for <a4>
## Warning: conversion failure on 'Ξ¤ΞτλΞΟ‚ στα ελληνΞΞΞ¬' in 'mbcsToSbcs': dot substituted for <ce>
## Warning: conversion failure on 'Ξ¤ΞτλΞΟ‚ στα ελληνΞΞΞ¬' in 'mbcsToSbcs': dot substituted for

我发现在 block 选项中指定 dev='cairo_pdf' 可以解决问题，但是在 html 输出中看不到该图。

> sessionInfo()
R version 3.1.1 (2014-07-10)
Platform: i386-w64-mingw32/i386 (32-bit)

locale:
[1] LC_COLLATE=Greek_Greece.1253  LC_CTYPE=Greek_Greece.1253    LC_MONETARY=Greek_Greece.1253 LC_NUMERIC=C                  LC_TIME=Greek_Greece.1253    

attached base packages:
 [1] datasets  grDevices splines   graphics  stats     grid      tcltk     utils     methods   base     

other attached packages:
 [1] tis_1.23            GGally_0.4.7        mratios_1.3.17      fpp_0.5             lmtest_0.9-33       expsmooth_2.02      fma_2.01           
 [8] tseries_0.10-32     forecast_5.4        xts_0.9-7           stringr_0.6.2       beeswarm_0.1.6      colorspace_1.2-4    latticeExtra_0.6-26
[15] RColorBrewer_1.0-5  amap_0.8-12         gridExtra_0.9.1     corrplot_0.73       psych_1.4.5         pgirmess_1.5.9      pastecs_1.3-18     
[22] boot_1.3-11         xtable_1.7-3        plyr_1.8.1          zoo_1.7-11          googleVis_0.4.5     RJSONIO_1.3-0       ggthemes_1.7.0     
[29] knitr_1.6           fBasics_3010.86     timeSeries_3010.97  timeDate_3010.98    MASS_7.3-33         RODBC_1.3-10        car_2.0-20         
[36] sos_1.3-8           brew_1.0-6          reshape2_1.4        scales_0.2.4        ggplot2_1.0.0       svSocket_0.9-57     TinnR_1.0-5        
[43] R2HTML_2.2.1        Hmisc_3.14-4        Formula_1.1-2       survival_2.37-7     lattice_0.20-29    

loaded via a namespace (and not attached):
 [1] cluster_1.15.2   coda_0.16-1      deldir_0.1-6     digest_0.6.4     evaluate_0.5.5   formatR_0.10     fracdiff_1.4-2   gtable_0.1.2     htmltools_0.2.4 
[10] labeling_0.2     LearnBayes_2.15  Matrix_1.1-4     munsell_0.4.2    mvtnorm_1.0-0    nlme_3.1-117     nnet_7.3-8       parallel_3.1.1   proto_0.3-10    
[19] quadprog_1.5-5   Rcpp_0.11.2      reshape_0.8.5    rgdal_0.8-16     rmarkdown_0.2.54 sp_1.0-15        spdep_0.5-74     splancs_2.01-34  stabledist_0.6-6
[28] svMisc_0.9-70    tools_3.1.1      yaml_2.1.13 

Answer 1

您可以在 knit 期间检查 rmarkdown.pandoc.to 选项的值，并动态设置设备:

my_output <- knitr::opts_knit$get("rmarkdown.pandoc.to")

if (my_output == "latex"){
  opts_chunk$set(dev='cairo_pdf', dev.args=list(cairo_pdf = list(family='Times New Roman')))
}