r - 在Bookdown（xelatex）的数学模式下使用Unicode字符(Using Unicode characters in math mode with Bookdown (xelatex))

Question

I try to use a Unicode character (U+2685) in math mode with Bookdown, I set mathfont: STIX Two Math (which contains this character), yet the resulting PDF contains an empty space.

(我尝试在Bookdown的数学模式下使用Unicode字符（U + 2685），并设置mathfont: STIX Two Math （包含此字符），但生成的PDF包含空白。)

(At the same time the HTML is correct.)

(（同时HTML是正确的。）)

What's wrong here?

(怎么了)

(My best guess is that I should perhaps use the unicode-math package. Unfortunately I can't include it in the preamble.tex as it is incompatible with the mathspec , but at the same time I see no way to get rid of mathspec ; it seems to be hardcoded in Bookdown that mathspec is usepackage d when xelatex is used.)

(（我的最佳猜测是，我也许应该使用unicode-math软件包。不幸的是，由于它与mathspec 不兼容 ，因此我无法将其包含在preamble.tex中，但与此同时，我也看不到摆脱mathspec ；在Bookdown中似乎硬编码为使用xelatex时mathspec是usepackage d。）)

Minimal reproducible example (showing index.Rmd , all other file is the same as with the default new project created with RStudio):

(最小的可重现示例（显示index.Rmd ，所有其他文件与使用RStudio创建的默认新项目相同）：)

--- 
title: "A Minimal Book Example"
author: "Yihui Xie"
date: "`r Sys.Date()`"
site: bookdown::bookdown_site
documentclass: book
link-citations: yes
description: "This is a minimal example of using the bookdown package to write a book. The output format for this example is bookdown::gitbook."
mainfont: STIX Two Math
mathfont: STIX Two Math
---

# Prerequisites

In text: ?.

In math mode: $?$.

This is how the result looks like:

(结果如下所示：)

  ask by Tamas Ferenci translate from so

Answer 1

现在（在更新rmarkdown ）已解决此问题，请参见此处 。