Evaluate a plot expression under a fixed random seed

Builds a plot with a reproducible random stream so randomised layers (jitter, most notably) land in the same place on every rebuild. Without this, any input change re-draws the jitter offsets, which makes points appear to jump around and leaves anything anchored to a point's position pointing at stale coordinates. The caller's random stream is restored afterwards.

Usage

with_stable_seed(expr, seed = 42L)

Arguments

expr

Expression producing the plot. Evaluated lazily, after the seed is set.

seed

Integer. Seed to build under.

Value

The value of expr.

Author

Jared Andrews

Examples

with_stable_seed(runif(2))
#> [1] 0.9148060 0.9370754
with_stable_seed(runif(2))
#> [1] 0.9148060 0.9370754