Cross Reference Subfigures in R Markdown

Question

I have a figure with subfigures in R Markdown. How do I cross-reference these in the text as Figure 1a, Figure 1b etc?

```{r figgy, fig.cap='Caption', echo = FALSE, fig.ncol = 2, out.width = "50%", fig.align = "center", fig.subcap=c('(a)', '(b)', '(c)')}
plot(1:10)
plot(cars, pch = 19)
boxplot(Sepal.Width ~ Species, data = iris)
```

Code from R Markdown Cookbook. I'm using bookdown::tufte_handout2

Answer 1

Use the \subref* command to refer to the subfigures. Usually, the cross-referencing syntax would be \subref*{<code-chunk-label>:<plot-serial-no>}. And I have used subrefformat=simple so that the reference style looks like 1a instead of 1(a).

---
title: Cross-referencing subfigures
output: 
  bookdown::tufte_handout2:
header-includes:
  - \usepackage[subrefformat=simple]{subfig}
---

```{r}
#| label: figgy
#| fig.cap: "Caption"
#| echo: false
#| fig.ncol: 2
#| out.width: "50%"
#| fig.align: "center"
#| fig.subcap: !expr c("A boring scatterplot", "Another scatterplot", "A boxplot")
#| fig.height: 3

plot(1:10)
plot(cars, pch = 19)
boxplot(Sepal.Width ~ Species, data = iris)
```

- Figure \subref*{fig:figgy-1} is a scatterplot
- Figure \subref*{fig:figgy-2} is another scatterplot
- Figure \subref*{fig:figgy-3} is a boxplot

---