cowplot (version 0.5.0)

draw_label: Draw a text label or mathematical expression.

Description

This function can draw either a character string or mathematical expression at the given coordinates. It works both on top of ggdraw and directly with ggplot, depending on which coordinate system is desired (see examples).

Usage

draw_label(label, x = 0.5, y = 0.5, hjust = 0.5, vjust = 0.5,
  fontfamily = "", fontface = "plain", colour = "black", size = 14,
  angle = 0, lineheight = 0.9, alpha = 1)

Arguments

label

String or plotmath expression to be drawn.

x

The x location of the label.

y

The y location of the label.

hjust

Horizontal justification

vjust

Vertical justification

fontfamily

The font family

fontface

The font face ("plain", "bold", etc.)

colour

Text color

size

Point size of text

angle

Angle at which text is drawn

lineheight

Line height of text

alpha

The alpha value of the text

Details

By default, the x and y coordinates specify the center of the text box. Set hjust = 0, vjust = 0 to specify the lower left corner, and other values of hjust and vjust for any other relative location you want to specify.

Examples

p <- ggplot(mtcars, aes(mpg, disp)) + geom_line(colour = "blue") + background_grid(minor='none')
c <- cor.test(mtcars$mpg, mtcars$disp, method='sp')
label <- substitute(paste("Spearman ", rho, "= ", estimate, ", P = ", pvalue),
                    list(estimate = signif(c$estimate, 2), pvalue = signif(c$p.value, 2)))
# adding label via ggdraw, in the ggdraw coordinates
ggdraw(p) + draw_label(label, .7, .9)
# adding label directly to plot, in the data coordinates
p + draw_label(label, 20, 400, hjust = 0, vjust = 0)