fortify.map: Fortify method for map objects

In ggplot2: Create Elegant Data Visualisations Using the Grammar of Graphics

Fortify method for map objects

Description

This function turns a map into a data frame that can more easily be plotted with ggplot2.

Usage

## S3 method for class 'map'
fortify(model, data, ...)

Arguments

model	map object
data	not used by this method
...	not used by this method

See Also

map_data() and annotation_borders()

Examples

if (require("maps")) {
ca <- map("county", "ca", plot = FALSE, fill = TRUE)
head(fortify(ca))
ggplot(ca, aes(long, lat)) +
  geom_polygon(aes(group = group))
}

if (require("maps")) {
tx <- map("county", "texas", plot = FALSE, fill = TRUE)
head(fortify(tx))
ggplot(tx, aes(long, lat)) +
  geom_polygon(aes(group = group), colour = "white")
}

ggplot2 documentation built on Sept. 11, 2025, 9:10 a.m.