Simple figure cross reference does not work

[steven-wooding]

I'm trying to get a simple figure cross reference to work:

---
title: "Testing cross referencing"
---

Some test type @fig-airquality

```{r}
#| label: fig-airquality

a <- c(1, 2, 3)
a
```

(The code does NOT have the trailing bracket but I can't work out how to get back ticks to render without it)

This fails with 'WARNING: Unable to resolve crossref @fig-airquality'

I'm sure I'm doing something really silly wrong, but I can't see what it is.

I'm running RStudio 2023.03.0+386 on macOS arm64 13.2.1 and Quarto version 1.3.310

Any suggestions much appreciated.

[dragonstyle]

Try adding a fig-cap to the code chunk- figures require captions...

Hope this fixes it!

[steven-wooding]

Thanks for the super speedy reply - I'm afraid it doesn't fix it. I now have:

---
title: "Testing cross referencing"
---

Some test type @fig-airquality

```{r}
#| label: fig-airquality
#| fig-cap: "Air quality"

a <- c(1, 2, 3)
a
```{

And still get the error "WARNING: Unable to resolve crossref @fig-airquality"
and in the output the cross reference is rendered as "Some test type ?@fig-airquality"

[rgaiacs]

Can you use some code that produces an image? For example,

```{r}
plot(c(1, 2, 3), c(1, 2, 1))
```

[dragonstyle]

That's a good catch - I think emitting a plot would fix it. To make a figure out of a non-plot, you can use figure divs, like:

:::{#fig-airquality2}
```{r}
a <- c(1, 2, 3)
a
```

A set of data about air quality
:::

[steven-wooding]

It looks like the 'producing a graphic' is the key thing. The figure caption (#| fig_cap:) is not necessary to make it work.

Big thanks for helping me solve this.

I'm trying to troubleshoot a failure to cross-reference in a more complicated document and it looks like in making a minimal example I've actually changed the problem :-(. I'll try and come up with a better example for the problem that started this.

[cscheid]

To respond to your code-formatting question: the way to get triple-ticks to work inside a code block is to use more ticks on the outside code block than on the inside. So, use four ticks to open a code block that includes triple ticks, etc.

[steven-wooding]

Thanks - much appreciated. I searched and found the instructions to use 'more back ticks' but I couldn't work out how to use the extra ticks!