r - 如何在 rmarkdown 中交叉引用表格和图表？

Question

我正在使用以下模板

---
title: "Nice try buddy"
author: "SpaceMan"
date: "13 December 2057"
output:
  bookdown::pdf_document2
header-includes:
- \usepackage{booktabs}
- \usepackage{longtable}
- \usepackage{array}
- \usepackage{multirow}
- \usepackage[table]{xcolor}
- \usepackage{wrapfig}
- \usepackage{float}
- \usepackage{colortbl}
- \usepackage{pdflscape}
- \usepackage{tabu}
- \usepackage{threeparttable}
- \usepackage{threeparttablex}
- \usepackage[normalem]{ulem}
- \usepackage{makecell}  
---
---
references:
- id: fenner2012a
  title: One-click science marketing
  container-title: Nature Materials
  volume: 11
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```

## Title

\begin{equation}
f\left(k\right)=\binom{n}{k}p^k\left(1-p\right)^{n-k} \label{eq:binom}
\end{equation}

You may refer to it using `\@ref(eq:binom)`, e.g., see Equation \@ref(eq:binom).
and not a nice citation! @fenner2012a


## Including Tables

You can also embed tables, for example:  \@ref(tab:tw)

```{r tw, echo=FALSE}
mytable
```

## References

其中mytable存储在R session 中并使用

生成

mytable <- head(cars) %>% kable(format = "latex", 
                                booktabs = T, 
                                caption = "Demo Table", 
                                escape = F) %>%
kable_styling(latex_options = 'HOLD_position')

现在，这应该可以工作，但是当我使用

编织文档时

rmarkdown::render('C:\\Users\\john\\Documents\\bbv.Rmd')

• 表格的交叉引用不存在!我只看到 ??
• table 上有这个奇怪的#tab东西 - 如何摆脱它？
• 目录就在这里，尽管我没有要求它

有什么想法可以解决这些问题吗？谢谢!

编辑:奇怪的#tab东西在重新启动后消失了。

Answer 1

问题在于，您在 R block 之外使用它，违背了 kable 的意图:

The kable() function will automatically generate a label for a table environment, which is the prefix tab: plus the chunk label.

https://bookdown.org/yihui/bookdown/tables.html

所以下面的解决方法肯定是比较hacky的。使用文件 foo.Rmd 与

---
output:
  bookdown::pdf_document2:
    toc: no
header-includes:
- \usepackage{float}
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```


## Including Tables

You can also embed tables, for example:  \@ref(tab:tw)

```{r tw, echo=FALSE}
mytable
```

You can also embed tables, for example:  \@ref(tab:tw2)

```{r tw2, echo=FALSE}
mytable2
```

Referencing images is easier: \@ref(fig:plt)

```{r plt, echo=FALSE, fig.cap = 'hello', fig.height=3} 
myplot 
``` 

可以使用第二个文件 foo.R 处理此文件:

library(knitr)
library(kableExtra)
# add the label to the options that would normally be populated from the chunk options
opts_current$append(list(label = "tw"))
mytable <- head(cars) %>% kable(format = "latex", 
                                booktabs = T, 
                                caption = "Demo Table", 
                                escape = F) %>%
  kable_styling(latex_options = 'HOLD_position')
opts_current$restore()

opts_current$append(list(label = "tw2"))
mytable2 <- tail(cars) %>% kable(format = "latex", 
                                booktabs = T, 
                                caption = "Demo Table", 
                                escape = F) %>%
  kable_styling(latex_options = 'HOLD_position')
opts_current$restore()

myplot <- ggplot(cars, aes(x = dist, y = speed)) + geom_point()

rmarkdown::render("foo.Rmd")

原则上，您也可以在 R 提示符下执行这些命令，但我尽量不直接使用提示符。顺便说一句，我没有得到您的代码的 (#tab) 输出。

但是，我认为不违背 kable 的工作方式更有意义。我可以理解，将数据操作与演示分离是有意义的。然而，从我的角度来看，创建表格是一种演示。因此，我不会在外部创建表，而是在外部创建数据。为了使这一点具体化，我们使用一个文件 bar.Rmd:

---
output:
  bookdown::pdf_document2:
    toc: no
header-includes:
- \usepackage{float}
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
library(kableExtra)
```

## Including Tables

You can also embed tables, for example:  \@ref(tab:tw)

```{r tw, echo=FALSE}
mydata %>% kable(format = "latex", 
                 booktabs = T, 
                 caption = "Demo Table", 
                 escape = F) %>%
  kable_styling(latex_options = 'HOLD_position')
```

与文件bar.R一起:

# insert data processing here
mydata <- head(cars)
rmarkdown::render("bar.Rmd")

这给了我相同的输出，并且数据处理(最初!)与演示文稿分开。