label_bquote: Backquoted labeller
label_bquote() offers a flexible way of labelling
facet rows or columns with plotmath expressions. Backquoted
variables will be replaced with their value in the facet.
label_bquote(rows = NULL, cols = NULL, default = label_value)
Backquoted labelling expression for rows.
Backquoted labelling expression for columns.
Default labeller function for the rows or the
columns when no plotmath expression is provided.
# The variables mentioned in the plotmath expression must be
# backquoted and referred to by their names.
p <- ggplot(mtcars, aes(wt, mpg)) + geom_point()
p + facet_grid(vs ~ ., labeller = label_bquote(alpha ^ .(vs)))
p + facet_grid(. ~ vs, labeller = label_bquote(cols = .(vs) ^ .(vs)))
p + facet_grid(. ~ vs + am, labeller = label_bquote(cols = .(am) ^ .(vs)))