Caption placed incorrect when using multiple include_graphics()

[hadley]

If I write

```{r fig1, fig.cap = "This is a caption", out.width = "33%", fig.show = "hold", echo = FALSE}
knitr::include_graphics("test-1.png")
knitr::include_graphics("test-2.png")
knitr::include_graphics("test-3.png")
```

The figure caption appears after test-1.png, instead of after test-3.png:

Full reprex here: fig-cap.zip

[hadley]

This is making "Mastering Shiny" look a little shoddy: https://mastering-shiny.org/action-dynamic.html#updating-inputs

[cderv]

Currently with knitr::include_graphics, you can pass a vector of paths like this

knitr::include_graphics(c("test-1.png", "test-2.png", "test-3.png"))

It will render like this

Internally, it is expected that the caption is placed after the last figure. a counter options fig.num try to calculate the number of figure in a chunk. Currently, if provided, this chunk options is replaced internally by the number to figure in knitr::include_graphics. That is why if you provide all three pngs in the same vector, the caption is correctly put under.

Did you already try this ? Do you call include_graphics 3 times for a reason here ?

If so, I think there is indeed improvement to make on how fig.num is computed and when.

Hope it helps.

[hadley]

I'm generating the screenshots with code, so I can work around the problem (now that I know how, thanks!), but it seems odd that I have to do something different with include_graphics() than I would with (e.g.) plot().

[cderv]

Yes I agree that knitr should be able to guess by itself. I already identified where to put some small changes

knitr/R/block.R

Lines 241 to 243 in c25df11

	# number of plots in this chunk
	if (is.null(options$fig.num))
	options$fig.num = if (length(res)) sum(sapply(res, evaluate::is.recordedplot)) else 0L

and

knitr/R/output.R

Line 557 in 0daf31b

options$fig.num = length(x)

It works already with your reprex but it needs more tests before a PR to see if it breaks anything and it it handles all cases.

working in branch fix-1771
Comparaison master...cderv:fix-1771

Just sharing the lead I follow...

[yihui]

Should be fixed now. Thanks for the report, and thank @cderv for the PR!

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