scale_identity: Use values without scaling

# NOT RUN { ggplot(luv_colours, aes(u, v)) +  geom_point(aes(colour = col), size = 3) +  scale_color_identity() +  coord_equal()  df <- data.frame(  x = 1:4,  y = 1:4,  colour = c("red", "green", "blue", "yellow") ) ggplot(df, aes(x, y)) + geom_tile(aes(fill = colour)) ggplot(df, aes(x, y)) +  geom_tile(aes(fill = colour)) +  scale_fill_identity()  # To get a legend guide, specify guide = "legend" ggplot(df, aes(x, y)) +  geom_tile(aes(fill = colour)) +  scale_fill_identity(guide = "legend") # But you'll typically also need to supply breaks and labels: ggplot(df, aes(x, y)) +  geom_tile(aes(fill = colour)) +  scale_fill_identity("trt", labels = letters[1:4], breaks = df$colour,  guide = "legend")  # cyl scaled to appropriate size ggplot(mtcars, aes(mpg, wt)) +  geom_point(aes(size = cyl))  # cyl used as point size ggplot(mtcars, aes(mpg, wt)) +  geom_point(aes(size = cyl)) +  scale_size_identity() # }