I just upgraded from ggplot2 0.9.1 to 0.9.2.1. The way POSIXlt times are mapped to colours has changed, and I don't know how to get back to the old behaviour.
Is there a way to get back the gradient scale in 0.9.2.1? (I did try to search the changelog and the mailing list, to no avail. Pointers to previous discussions would of course be appreciated.)
library(reshape)
library(ggplot2)
dat <- mutate(data.frame(x=seq(0,10,0.1)),
y = sin(x),
t = as.POSIXlt(sprintf("2012-07-18 20:%d:%f", as.integer(x), x)))
summary(dat)
ggplot.version <- sessionInfo("ggplot2")$otherPkgs$ggplot2$Version
cat("this is ggplot2 version", ggplot.version, "\n")
p <- ggplot(dat) + geom_point(aes(x=x, y=y, color=t))
ggsave(sprintf("time-color-%s.png", ggplot.version))