以与 Rmarkdown 中文本的默认字体相同的字体输出代码

Question

这是一个代表：

---
date : 2018-May-27
output:
    pdf_document:
        latex_engine: xelatex
monofont: "Computer Modern"
title: "Testing Rmarkdown"
---

```{r,comment = NA}

Gender <- gl(2,1000,labels = c("Men","Women"))
SmokerM <- sample(c("Y","N"),1000,replace = T , prob = c(.3,.7))
SmokerW <- sample(c("Y","N"),1000,replace = T , prob = c(.5,.5))
Smoker <- c(SmokerM,SmokerW)

mydata  <- data.frame(Gender,Smoker)
table(mydata$Gender,mydata$Smoker)
```
This is some running text(in the Computer Modern font).

我只想要文档中的一种字体，即。文本的默认字体。为此，我添加了 monofont: "Computer Modern" 行（通过此我试图告诉软件以与文本相同的字体创建代码输出）。当我尝试从上述 Rmarkdown 文件创建 PDF 时出现以下错误。我有一个 Ubuntu 系统。 我怎样才能解决这个问题 ？

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!
! fontspec error: "font-not-found"
! 
! The font "Computer Modern" cannot be found.
! 
! See the fontspec documentation for further information.
! 
! For immediate help type H <return>.
!...............................................  

这是对此处发布的原始查询的后续查询：[原始查询]Fonts for Rmarkdown document

Answer 1

实际上，默认使用的不是计算机现代，而是其接近的相对拉丁现代。所以你可以试试：

---
date : 2018-May-26
output:
    pdf_document:
        latex_engine: xelatex
mainfont: Latin Modern Roman
monofont: Latin Modern Roman
title: "Testing Rmarkdown"
---

```{r,comment = NA}

Gender <- gl(2,1000,labels = c("Men","Women"))
SmokerM <- sample(c("Y","N"),1000,replace = T , prob = c(.3,.7))
SmokerW <- sample(c("Y","N"),1000,replace = T , prob = c(.5,.5))
Smoker <- c(SmokerM,SmokerW)

mydata  <- data.frame(Gender,Smoker)
table(mydata$Gender,mydata$Smoker)
knitr::kable(table(mydata$Gender,mydata$Smoker))
```

This is a text in the body of the document.What font is this ? What is
font for the output of table ? How can we change these 2 fonts ? What 
other categories of items are there in an Rmarkdown which have different
fonts ?   

由于您有一个 Ubuntu 系统，您可以使用fc-list 查看系统上安装的所有字体，这些字体可用于 XeLaTeX。

或者，如果你不想使用 XeLaTeX，你可以使用

output:
    pdf_document
header-includes:
    - \renewcommand*{\ttdefault}{lmr}

在标题中。