knitr - exclude chunks from `purl(…)`?

Question

When I purl/tangle a document to extract the R chunks into a script, is there any way to:

• exclude an arbitrary chunk (by name say)?
• if not, exclude a

Answer 1

Since knitr 1.3, there is a new chunk option purl = TRUE/FALSE that allows one to include/exclude certain code chunks for purl().

```{r test, purl=FALSE}
library(MASS)
```