Annotations on the axis

annotate_y_axis(
  label,
  y,
  side = waiver(),
  print_label = TRUE,
  print_value = TRUE,
  print_both = TRUE,
  parsed = FALSE,
  ...
)

annotate_x_axis(
  label,
  x,
  side = waiver(),
  print_label = TRUE,
  print_value = TRUE,
  print_both = TRUE,
  parsed = FALSE,
  ...
)

Arguments

label: Text to print
y, x: Position of the annotation.
side: left or right, or top or bottom side to print annotation
print_label, print_value, print_both: Logical; what to show on annotation. Label and/or value. print_both is shortcut for setting both print_label and print_value. When both is TRUE, uses argument sep to separate the label and value.
parsed: Logical (default FALSE), when TRUE, uses mathplot for outputting expressions. See section "Showing values".
...: Style settings for label and tick: colour, hjust, vjust, size, fontface, family, rot. When waiver() (default), the relevant theme element is used.

Showing values

See plotmath for using mathematical expressions. The function uses a simple replacement strategy where the literal strings .(y) and .(val) are replaced by the value after round of to a number of digits, as given by argument digits.

Examples

library(ggplot2)

p <- ggplot(mtcars, aes(mpg, hp, colour=disp)) + geom_point()

l <- p + annotate_y_axis('mark at', y=200, tick=TRUE)
l


(l + annotate_x_axis('| good economy ->', x=25, print_value=FALSE, hjust=0, tick=TRUE))


l + annotate_y_axis("x^2 == .(y)", y=150, parsed=FALSE,  tick=FALSE) +
    annotate_y_axis("x^2 + bar(x) == .(y)", y=mean(mtcars$hp), parsed=TRUE, tick=TRUE)


l + annotate_y_axis("bar(x) == .(y)", y = mean(mtcars$hp),  parsed=TRUE, tick=FALSE) 

# use double equal signs, or the output becomes '=(...)' for some reason.

l + annotate_y_axis('this is midway', y=sum(range(mtcars$hp))/2, print_value = FALSE, side='left')


# work around if an axis only contains parsed expressions
p + annotate_y_axis("bar(x) == .(y)", y = mean(mtcars$hp),  parsed=TRUE, tick=FALSE) +
  annotate_y_axis("some long string", y=100, tick=FALSE, print_value=FALSE, colour=NA)



# Works together with other functions
p <- p + theme_light() + theme(panel.border=element_blank(),
                               axis.line = element_line(), 
                               axis.ticks = element_line(colour='black')) 
p + coord_capped_cart(bottom='right') + 
  annotate_y_axis('More than I\ncan afford', y=125, 
                  print_value=FALSE, tick=TRUE)