coord_trans is different to scale transformations in that it occurs after statistical transformation and will affect the visual appearance of geoms - there is no guarantee that straight lines will continue to be straight.

coord_trans(x = "identity", y = "identity", limx = NULL, limy = NULL,
  xtrans, ytrans)

Arguments

x, y

transformers for x and y axes

limx, limy

limits for x and y axes. (Named so for backward compatibility)

xtrans, ytrans

Deprecated; use x and y instead.

Details

Transformations only work with continuous values: see trans_new for list of transformations, and instructions on how to create your own.

Examples

# See ?geom_boxplot for other examples # Three ways of doing transformation in ggplot: # * by transforming the data ggplot(diamonds, aes(log10(carat), log10(price))) + geom_point()
# * by transforming the scales ggplot(diamonds, aes(carat, price)) + geom_point() + scale_x_log10() + scale_y_log10()
# * by transforming the coordinate system: ggplot(diamonds, aes(carat, price)) + geom_point() + coord_trans(x = "log10", y = "log10")
# The difference between transforming the scales and # transforming the coordinate system is that scale # transformation occurs BEFORE statistics, and coordinate # transformation afterwards. Coordinate transformation also # changes the shape of geoms: d <- subset(diamonds, carat > 0.5) ggplot(d, aes(carat, price)) + geom_point() + geom_smooth(method = "lm") + scale_x_log10() + scale_y_log10()
ggplot(d, aes(carat, price)) + geom_point() + geom_smooth(method = "lm") + coord_trans(x = "log10", y = "log10")
# Here I used a subset of diamonds so that the smoothed line didn't # drop below zero, which obviously causes problems on the log-transformed # scale # With a combination of scale and coordinate transformation, it's # possible to do back-transformations: ggplot(diamonds, aes(carat, price)) + geom_point() + geom_smooth(method = "lm") + scale_x_log10() + scale_y_log10() + coord_trans(x = scales::exp_trans(10), y = scales::exp_trans(10))
# cf. ggplot(diamonds, aes(carat, price)) + geom_point() + geom_smooth(method = "lm")
# Also works with discrete scales df <- data.frame(a = abs(rnorm(26)),letters) plot <- ggplot(df,aes(a,letters)) + geom_point() plot + coord_trans(x = "log10")
plot + coord_trans(x = "sqrt")