Highlight

library(tidyverse)

#> ── Attaching packages ─────────────────────────────────────── tidyverse 1.3.0 ──

#> ✔ ggplot2 3.3.2     ✔ purrr   0.3.4
#> ✔ tibble  3.0.1     ✔ dplyr   1.0.0
#> ✔ tidyr   1.1.0     ✔ stringr 1.4.0
#> ✔ readr   1.3.1     ✔ forcats 0.5.0

#> ── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
#> ✖ dplyr::filter() masks stats::filter()
#> ✖ dplyr::lag()    masks stats::lag()

Use the parameter set by the user (or its default).

highlight <- pressure %>% filter(temperature > params$min_temp)

Plot.

ggplot(pressure, aes(temperature, pressure)) +
  geom_point() +
  geom_point(data = highlight, color = "red")