windows – R markdown v2 to pdf.当绘图中的非拉丁字符时转换错

---
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="Τ?τλο? στα ελληνικ?")
```

在绘图之前,用pdf编织产生如下几行(当然可以省略警告= FALSE),它不显示非英文标题.

## Warning: conversion failure on 'Ξ¤ΞΟ?Ξ?ΞΟ? Ο?Ο?Ξ± ΞμΞ?Ξ?Ξ·Ξ?ΞΞΞ?' in 'mbcsToSbcs': dot substituted for <ce>
## Warning: conversion failure on 'Ξ¤ΞΟ?Ξ?ΞΟ? Ο?Ο?Ξ± ΞμΞ?Ξ?Ξ·Ξ?ΞΞΞ?' in 'mbcsToSbcs': dot substituted for <a4>
## Warning: conversion failure on 'Ξ¤ΞΟ?Ξ?ΞΟ? Ο?Ο?Ξ± ΞμΞ?Ξ?Ξ·Ξ?ΞΞΞ?' in 'mbcsToSbcs': dot substituted for <ce>
## Warning: conversion failure on 'Ξ¤ΞΟ?Ξ?ΞΟ? Ο?Ο?Ξ± ΞμΞ?Ξ?Ξ·Ξ?ΞΞΞ?' in 'mbcsToSbcs': dot substituted for

我发现在块选项中指定dev =’cairo_pdf’可以解决问题,但是在html输出中不能看到该图.

> 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