Creating rmarkdown rendered to .docx with citations and superscripts in caption

Question

I am creating a .docx document from rmarkdown. I use bookdown rendering as I like to use text references. I'm having difficulty with the caption for a figure that contains two plots, for which I need a caption with superscripts. Rendering to pdf works fine, but the caption does not appear in the docx.

---
title: "Untitled"
output:
  bookdown::word_document2: 
    number_sections: false
  bookdown::pdf_document2:
    number_sections: false
  bookdown::html_document2: 
    number_sections: false
date: "2023-06-19"
always_allow_html: false
bibliography: C:/Users/mrd19rph/OneDrive - Bangor University/PhD Folder/General introduction/library.bib
---

'''{r setup, include=FALSE}
library(knitr)
knitr::opts_chunk$set(echo = FALSE, warning = F, message = F)

library(ggplot2)
'''

Details are shown in Figures \@ref(fig:testfig) and \@ref(fig:testfig2).

(ref:testfigcap) Caption for figure with a citation [@Borg1967].

'''{r testfig, out.height= "20%", fig.cap="(ref:testfigcap)"}
ggplot(iris, aes(x = Sepal.Length  , y = Petal.Length))+geom_point()
'''

Text here.

(ref:testfigcap2) Caption containing text^superscript^ for A: by hp and B by wt


'''{r testfig2, fig.show='hold', out.width= "55%",  fig.cap= '(ref:testfigcap2)'}
plota = ggplot(mtcars, aes(x= mpg, y =hp))+geom_point()+
  labs(title = "A")

plotb = ggplot(mtcars, aes(x= mpg, y =wt))+geom_point()+
  labs(title = "B")

plota
plotb
'''
The use of the text reference for a caption  works for the single plot figure, but not for the double plot figure.

PDF rendering

Word rendering

Answer 1

I think this is a limitation of Word, i.e. you can't have a caption for two separate figures. One possible option to fix that would be to create one plot by glueing your two charts together using e.g. gridExtra::grid.arrange or patchwork or ...:

---
title: "Untitled"
output:
  bookdown::word_document2: 
    number_sections: false
  bookdown::pdf_document2:
    number_sections: false
  bookdown::html_document2: 
    number_sections: false
date: "2023-06-19"
always_allow_html: false
---

```{r setup, include=FALSE}
library(knitr)
knitr::opts_chunk$set(echo = FALSE, warning = F, message = F)

library(ggplot2)
```

Details are shown in Figures \@ref(fig:testfig) and \@ref(fig:testfig2).

(ref:testfigcap) Caption for figure with a citation [@Borg1967].

```{r testfig, out.height= "20%", fig.cap="(ref:testfigcap)"}
ggplot(iris, aes(x = Sepal.Length, y = Petal.Length)) +
  geom_point()
```

Text here.

(ref:testfigcap2) Caption containing text ^superscript^ for A: by hp and B by wt


```{r testfig2, fig.cap= '(ref:testfigcap2)'}
plota <- ggplot(mtcars, aes(x = mpg, y = hp)) +
  geom_point() +
  labs(title = "A")

plotb <- ggplot(mtcars, aes(x = mpg, y = wt)) +
  geom_point() +
  labs(title = "B")

gridExtra::grid.arrange(plota, plotb, nrow = 1)
```

The use of the text reference for a caption  works for the single plot figure, but not for the double plot figure.