bootstrapper: Create a bootstrapper function useful for repeated...

In clauswilke/ungeviz: Tools for visualizing uncertainty with ggplot2

Description

Create a bootstrapper function useful for repeated reproducible bootstrapping

Usage

bootstrapper(times, group = NULL, seed = NULL, key = ".draw",
  row = ".row", id = ".id", original_id = ".original_id",
  copies = ".copies")

Arguments

times	Number of independent bootstrap draws to perform.
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 bootstrapped row originates.
copies	Name (as character) of the column that reports how often a specific original row has been oversampled.

See Also

sampler()

Examples

bs <- bootstrapper(3)
bs(data.frame(letter = letters[1:4]))

library(ggplot2)
library(dplyr)
ggplot(iris, aes(Sepal.Length, Sepal.Width)) +
  geom_point() +
  geom_smooth(data = bootstrapper(5, Species), aes(group = .draw), se = FALSE) +
  facet_wrap(~Species)

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

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

# incorrect: bootstrapping ungrouped dataset leads to missing category C
ggplot(df, aes(type, y)) +
  geom_pointrange(data = bootstrapper(6, seed = 562), stat = "summary") +
  facet_wrap(~.draw)

# correct: bootstrapping within groups
ggplot(df, aes(type, y)) +
  geom_pointrange(data = bootstrapper(6, type, seed = 562), stat = "summary") +
  facet_wrap(~.draw)

# also correct: use grouped data frame
ggplot(group_by(df, type), aes(type, y)) +
  geom_pointrange(data = bootstrapper(6, seed = 562), stat = "summary") +
  facet_wrap(~.draw)

## Not run: 
library(gganimate)

set.seed(69527)
x <- rnorm(15)
data <- data.frame(
  x,
  y = x + 0.5*rnorm(15)
)

bs <- bootstrapper(9)

p <- ggplot(data, aes(x, y)) +
  geom_point(shape = 21, size = 6, fill = "white") +
  geom_text(label = "0", hjust = 0.5, vjust = 0.5, size = 10/.pt) +
  geom_point(data = bs, aes(group = .row), shape = 21, size = 6, fill = "blue") +
  geom_text(
    data = bs, aes(label = .copies, group = .row),
    hjust = 0.5, vjust = 0.5, size = 10/.pt, color = "white"
  ) +
  geom_smooth(data = bs, method = "lm", se = FALSE) +
  ggtitle("Bootstrap demonstration") +
  theme_bw()

p + facet_wrap(~.draw)
p + transition_states(.draw, 1, 1) +
  enter_fade() + exit_fade()

## End(Not run)

clauswilke/ungeviz documentation built on May 16, 2019, 3:10 p.m.