更改 RMD 摘要的行间距？

Question

是否可以将我的 YAML header 中指定的摘要行间距更改为单行间距 space，同时将文档的其余部分保留为双行 space？我的 YAML 如下：

output:  pdf_document
number_sections: true
title: | 
  | My Title
author: 
- Me
header-includes:
    - \usepackage{setspace}\doublespacing
    - \usepackage{float}
abstract: "My abstract"
keywords: "My keywords"
date: "`r format(Sys.time(), '%B %d, %Y')`"
geometry: margin=1in
fontsize: 12pt
spacing: double
fig_caption: yes
indent: true
---

我试过像这样包装摘要，但没有成功：

abstract: 
    - \usepackage{setspace}\singlespacing
"My abstract"
    - \end{singlespacing}

Answer 1

摘要是自动换行的，所以前面用\singlespacing就可以了：

---
output:  pdf_document
number_sections: true
title: | 
  | My Title
author: 
- Me
header-includes:
    - \usepackage{setspace}\doublespacing
    - \usepackage{float}
abstract: \singlespacing My abstract which has to be long enough to take multiple
  lines otherwise one does not see the effect of single-spacing.
keywords: "My keywords"
date: "`r format(Sys.time(), '%B %d, %Y')`"
geometry: margin=1in
fontsize: 12pt
fig_caption: yes
indent: true
---


## R Markdown

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>.

结果：

更改 RMD 摘要的行间距？

Change line spacing for RMD abstract?

yaml

knitr

r-markdown