问题
I would like to show a nice cross-reference to a picture in the HTML document I'm creating with R Markdown. However, even if I followed the bookdown section on cross-references, I cannot get the reference to show in the final HTML output. I'm working in R Studio, if that helps. .Rmd file:
---
title: "ppp"
author: "ppp"
date: "July 4, 2017"
output:
html_document:
fig_caption: yes
---
```{r setup, include=FALSE}
library(knitr)
opts_chunk$set(echo = FALSE)
```
```{r foo, fig.cap="$f_{p}$ as a function of $g$ for various values of $r=\\frac{\\rho_{w}}{\\rho_{a}}$"}
# All defaults
include_graphics("download.jpg")
```
A cross-reference to figure \@ref(fig:foo).
The output I get is
So the caption is rendering correctly, but the cross-reference is not being created. How do I fix that?
回答1:
I'm not sure. But are you using bookdown? If you follow https://bookdown.org/yihui/bookdown/get-started.html, and use bookdown project as in https://github.com/yihui/bookdown-minimal. Then you should get the result you want.
For example, I use https://github.com/yihui/bookdown-minimal and modify the index.Rmd to something like this, and the cross reference shows correctly.
---
title: "A Book"
author: "Frida Gomam"
site: bookdown::bookdown_site
documentclass: book
output:
bookdown::gitbook: default
bookdown::pdf_book: default
---
{r foo, fig.cap="$f_{p}$ as a function of $g$ for various values of $r=\\frac{\\rho_{w}}{\\rho_{a}}$", echo=FALSE}
# All defaults
knitr::include_graphics("download.png")
A cross-reference to figure \@ref(fig:foo).
Update: Modify the output field to bookdown::html_document2 seems to generate the html document similar to rmarkdown::html_document.
来源：https://stackoverflow.com/questions/45018180/cross-reference-to-figure-in-r-markdown-with-html-output-is-not-working