stat_calc.R

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# ggplot2: Bug or Feature?
#
# Problem: stat_summary is calculated after axes are transformed.
#
# Expected:
#   Median at x=0 is 0, and median at x=1 is 1
#   Expect line from (0, 0) to (1, 1)
#
# Actual
#   Get a line from (0, 1) to (1, 1)
#   Because y values are log transformed first,
#   any zero values get replaced with Inf.  These
#   Inf values are then excluded from the median calculation
#   such that the median at x=0 is the median(1) = 1
#
# Is there an option to have stat_summary calculated before axis transform?
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
df = data.frame(
  x = c(0,0,0, 1,1,1),
  y = c(0,0,1, 1,1,1))

ggplot(df, aes(x, y))+
  stat_summary(fun.y=median,geom='line')+
  scale_y_log10()