print.ggplot: Explicitly draw plot

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

Explicitly draw plot

Description

Generally, you do not need to print or plot a ggplot2 plot explicitly: the default top-level print method will do it for you. You will, however, need to call print() explicitly if you want to draw a plot inside a function or for loop.

Usage

## S3 method for class 'ggplot'
print(x, newpage = is.null(vp), vp = NULL, ...)

## S3 method for class 'ggplot'
plot(x, newpage = is.null(vp), vp = NULL, ...)

Arguments

x	plot to display
newpage	draw new (empty) page first?
vp	viewport to draw plot in
...	other arguments not used by this method

Value

Invisibly returns the original plot.

Examples

colours <- list(~class, ~drv, ~fl)

# Doesn't seem to do anything!
for (colour in colours) {
  ggplot(mpg, aes_(~ displ, ~ hwy, colour = colour)) +
    geom_point()
}

# Works when we explicitly print the plots
for (colour in colours) {
  print(ggplot(mpg, aes_(~ displ, ~ hwy, colour = colour)) +
    geom_point())
}

ggplot2 documentation built on June 22, 2024, 11:35 a.m.