Learn R Programming

ggplot2 (version 2.2.1)

print.ggplot: 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

"print"(x, newpage = is.null(vp), vp = NULL, ...)
"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 result of ggplot_build, which is a list with components that contain the plot itself, the data, information about the scales, panels etc.

Examples

Run this code
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())
}

Run the code above in your browser using DataLab