get_data: Get the data set used by a plot or layer

In rstudio-education/ggcheck: Inspect 'ggplot2' Plots for Automated Grading in Learning Exercises

Get the data set used by a plot or layer

Description

get_data returns the data set used by a ggplot object or a single layer extracted from the object with get_geom_layer.

Usage

get_data(p, local_only = FALSE)

Arguments

p	A ggplot object or a layer extracted from a ggplot object with get_geom_layer.
local_only	TRUE or FALSE. Should get_data onbly return data defined locally in the layer?

Details

When passed a ggplot object (i.e. a plot), get_data will return only the data that has been set globally with ggplot.

When passed a single layer from a plot, the behavior of get_data will depend on the local_only argument passed to .... If local_only = TRUE, get_data will return only the data set, if any, that was defined locally in the function that created the layer. If local_only = FALSE, get_data will return the data used by the layer, whether or not that data was defined globally in ggplot or locally.

Value

A data frame. If no data set is found, get_data returns NULL

See Also

Other functions for checking data: ith_data_is(), ith_data(), uses_data()

Examples

require(ggplot2)
d2 <- head(mpg)
p <- ggplot(data = mpg, mapping = aes(x = displ, y = hwy)) +
  geom_point(data = d2, color = "red") +
  geom_point()
get_data(p)
get_data(get_geom_layer(p, i = 1))

rstudio-education/ggcheck documentation built on May 12, 2023, 11:33 a.m.