R: Obtain the figure filenames for a chunk

fig_chunk {knitr} | R Documentation

## Obtain the figure filenames for a chunk

### Description

Given a chunk label, the figure file extension, the figure number(s), and the chunk option `fig.path`, return the filename(s).

### Usage

    fig_chunk(label, ext = "", number, fig.path = opts_chunk$get("fig.path"))

### Arguments

`label` | the chunk label
`ext` | the figure file extension, e.g. `png` or `pdf`
`number` | the figure number (by default `1`)
`fig.path` | the chunk option `fig.path`

### Details

This function can be used in an inline R expression to write out the figure filenames without hard-coding them. For example, if you created a plot in a code chunk with the label `foo` and figure path ‘my-figure/’, you are not recommended to use hard-coded figure paths like \includegraphics{my-figure/foo-1.pdf} (in ‘.Rnw’ documents) or ![](my-figure/foo-1.png) (R Markdown) in your document. Instead, you should use \Sexpr{fig_chunk('foo', 'pdf')} or ![](`r fig_chunk('foo', 'png')`).

You can generate plots in a code chunk but not show them inside the code chunk by using the chunk option `fig.show = 'hide'`. Then you can use this function if you want to show them elsewhere.

### Value

A character vector of filenames.

### Examples

    library(knitr)
    fig_chunk("foo", "png")
    fig_chunk("foo", "pdf")
    fig_chunk("foo", "svg", 2)  # the second plot of the chunk foo
    fig_chunk("foo", "png", 1:5)  # if the chunk foo produced 5 plots

[Package knitr version 1.16 Index]