ggtikzCanvas {ggtikz}

Create a canvas to store TikZ annotations to a ggplot.

Description

Annotations can be made relative to the whole plot, to a panel, or to data coordinates (of individual panels).

Usage

ggtikzCanvas(gg_plot)

Arguments

gg_plot

A ggplot object on which annotations should be made.

Details

This function provides a canvas for TikZ annotations, and does not draw anything by itself. Its purpose is to provide information about the underlying ggplot object for coordinate calculations.

Value

A ggtikzCanvas object, to which annotations can be added.

See Also

grid.tikzAnnotate for annotation of base graphics.

ggtikz for a helper function for quick one-step annotations.

ggtikzAnnotation for more information about creating and adding ggtikz annotations.

Examples

## Not run: 
library(ggplot2)
library(tikzDevice)
library(ggtikz)
p <- ggplot(mtcars, aes(disp, mpg)) + geom_point()

# Create a TikZ canvas on the plot
canvas <- ggtikzCanvas(p)

# Create annotations to add to the canvas

# Circle in the center of the plot
annotation1 <- ggtikzAnnotation(
   "\\fill[red] (0.5,0.5) circle (2mm);",
   xy = "plot")

# Arrow to data coordinate (400,20)
annotation2 <- ggtikzAnnotation(
   "\\draw[<-] (400,20) -- ++(0,2.5);",
   xy = "data", panelx = 1, panely = 1)

out <- tempfile(fileext = ".tikz")
tikz(out)
# First, draw the original plot
p
# Then, add the annotations to the canvas and draw it
canvas + annotation1 + annotation2
dev.off()

## End(Not run)