knitr (version 1.28)

rand_seed: An unevaluated expression to return .Random.seed if exists

Description

This expression returns .Random.seed when eval(rand_seed) and NULL otherwise.

Usage

rand_seed

Details

It is designed to work with opts_chunk$set(cache.extra = rand_seed) for reproducibility of chunks that involve with random number generation. See references.

References

https://yihui.org/knitr/demo/cache/

Examples

# NOT RUN {
eval(rand_seed)
rnorm(1)  # .Random.seed is created (or modified)
eval(rand_seed)
# }