Coming from this example (pasted here)
trans_cube <- trans_new(name = "cube root",
transform = cube_root,
inverse = cube)
# dummy data
plot_data <- data.frame(x = 1:10,
y = cube(1:10))
# without applying a transform
ggplot(plot_data, aes(x = x, y = y)) +
geom_point()
# applying a transform
ggplot(plot_data, aes(x = x, y = y)) +
geom_point() +
coord_trans(y = trans_cube)
Why the simple transformation of just adding a constant (using scales::trans_new) won't work?
trans_add <- trans_new(name = "add",
transform = function(x) x + 200,
inverse = function(x) x -200)
ggplot(plot_data, aes(x = x, y = y)) + geom_point() +
coord_trans(y = trans_add )
The reason I'm asking is because I would like to back transform my y-axis and I need to do it using coord_trans or scale_y_continuous or similar.
UPDATE
I managed to show the back transformation with custom breaks by using the following, however I would like to know why the trans_new doesn't work.
fun_sc_back <- function(x){x*187+266} # transform
fun_sc <- function(x){(x-266)/187} # inverse
p_tr +
scale_y_continuous(breaks =fun_sc(c(250, 500, 750)), labels=fun_sc_back)
