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Surprise Map Geom

Source: R/ggplot2-geom.R
geom_surprise.Rd

A convenience geom that combines stat_surprise with geom_sf for easy creation of surprise maps.

Usage

geom_surprise(
  mapping = NULL,
  data = NULL,
  position = "identity",
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE,
  fill_type = c("surprise", "signed"),
  models = c("uniform", "baserate", "funnel"),
  color = NA,
  colour = color,
  linewidth = 0.1,
  ...
)

Arguments

mapping

Aesthetic mapping created by ggplot2::aes(). Required aesthetics are geometry (from sf) and observed. Optional aesthetics include expected and sample_size.

data

Data (typically an sf object)

position

Position adjustment

na.rm

Remove NA values?

show.legend

Show legend?

inherit.aes

Inherit aesthetics from ggplot?

fill_type

Type of surprise for fill aesthetic:

  • "surprise": Unsigned surprise (always positive)

  • "signed": Signed surprise (positive = higher than expected, negative = lower than expected)

models

Character vector of model types to use. Options: "uniform", "baserate", "gaussian", "sampled", "funnel"

color, colour

Border color for polygons

linewidth

Border line width

...

Additional arguments passed to the layer

Value

A list of ggplot2 layers

Aesthetics

geom_surprise understands the following aesthetics:

geometry

sf geometry column (required)

observed

Observed values (required)

expected

Expected values (optional, for base rate model)

sample_size

Sample sizes (optional, for funnel model)

fill

Mapped to surprise by default

color/colour

Border color

Examples

library(ggplot2)
#> Warning: package ‘ggplot2’ was built under R version 4.5.2
library(sf)
#> Warning: package ‘sf’ was built under R version 4.5.2
#> Linking to GEOS 3.13.0, GDAL 3.8.5, PROJ 9.5.1; sf_use_s2() is TRUE

nc <- st_read(system.file("shape/nc.shp", package = "sf"), quiet = TRUE)

# Basic surprise map - geometry must be mapped explicitly
ggplot(nc) +
  geom_surprise(aes(geometry = geometry, observed = SID74, expected = BIR74)) +
  scale_fill_surprise()


# Signed surprise with diverging scale
ggplot(nc) +
  geom_surprise(
    aes(geometry = geometry, observed = SID74, expected = BIR74),
    fill_type = "signed"
  ) +
  scale_fill_surprise_diverging()


# Customize appearance
ggplot(nc) +
  geom_surprise(
    aes(geometry = geometry, observed = SID74, expected = BIR74),
    color = "white",
    linewidth = 0.2
  ) +
  scale_fill_surprise() +
  theme_minimal()