Q:

Using facet_trelliscope without defining axis limits

Using facet_trelliscope from trelliscopejs this works:
library(trelliscopejs)
library(ggplot2)

x <- 1:10
y <- 1:10
group <- rep(c("A","B"),5)

df <- data.frame(group, x, y)

ggplot(df, aes(x, y)) + geom_point() + 
  xlim(0, 10) + ylim(0, 10) +
  facet_trelliscope(~group)

But this doesn't:
ggplot(df, aes(x, y)) + geom_point() + 
  facet_trelliscope(~group)

It throws up this error:
Error in scale_fn() : could not find function "scale_fn"

My question is, do axis limits always need to be defined for facet_trelliscope to work? 

A:

Thanks both it was indeed a package error.  If anyone sees the error in future just remove and re-install ggplot2. 