ungeviz (version 0.1.0)

sampler: Create a sampler function useful for repeated reproducible sampling

Description

Create a sampler function useful for repeated reproducible sampling

Usage

sampler(times, size = 1, replace = FALSE, group = NULL,
  seed = NULL, key = ".draw", row = ".row", id = ".id",
  original_id = ".original_id")

Arguments

times

Number of independent sampling draws to perform.

size

Sample size for each random sample.

replace

Bool indicating whether sampling should occur with or without replacement.

group

An optional expression setting up the grouping to use for bootstrapping. If not provided, any grouping present in the original dataset will be used.

seed

Random seed to use.

key

Name (as character) of the column that will hold an integer running from 1 to times indicating the bootstrap replicate.

row

Name (as character) of the column that will hold an integer counting rows in the final bootstrapped dataset. Useful for animations with gganimate.

id

Name (as character) of the column that will hold an integer running from 1 to n for each bootstrap, where n is the number of observations in each group.

original_id

Name (as character) of the column that indicates the row from which the sampled row originates.

See Also

bootstrapper()

Examples

# NOT RUN {
spl <- sampler(3, 2)
spl(data.frame(letter = letters[1:4]))

library(ggplot2)
library(dplyr)
ggplot(iris, aes(Sepal.Length, Sepal.Width)) +
  geom_point(aes(color = Species), alpha = 0.3) +
  geom_point(
    data = sampler(1, 5, group = Species),
    aes(fill = Species),
    color = "black", shape = 21
  ) +
  theme_bw()

# it is important to set grouping correctly for sampling
set.seed(1234)

df <- data.frame(
  type = c(rep("A", 100), rep("B", 10), rep("C", 3)),
  y = rnorm(113)
)

# incorrect: sampling ungrouped dataset leads to missing data
# in some categories
ggplot(df, aes(type, y)) +
  geom_pointrange(
    data = sampler(6, 3, replace = TRUE, seed = 559),
    stat = "summary"
  ) +
  facet_wrap(~.draw)

# correct: sampling within groups
ggplot(df, aes(type, y)) +
  geom_pointrange(
    data = sampler(6, 3, replace = TRUE, group = type, seed = 559),
    stat = "summary"
  ) +
  facet_wrap(~.draw)

# also correct: use grouped data frame
ggplot(group_by(df, type), aes(type, y)) +
  geom_pointrange(
    data = sampler(6, 3, replace = TRUE, seed = 559),
    stat = "summary"
  ) +
  facet_wrap(~.draw)

# }
# NOT RUN {
library(gganimate)

p <- ggplot(iris, aes(Sepal.Length, Species, color = Species)) +
  geom_point(color = "grey50", alpha = 0.3, size = 2) +
  geom_point(data = sampler(20, 1, group = Species), size = 4) +
  scale_color_brewer(type = "qual", palette = 2, guide = "none") +
  theme_bw()

p + facet_wrap(~.draw)
p + transition_states(.draw, 1, 2)
# }