Use this to extract x and y ranges from ggplot, dealing with changes in version
getPlotRanges(h)a list of x and y ranges
Other plot help:
AD2BP_trans(),
BP2AD_trans(),
axisLabel(),
bin2d(),
geoChronRPlotTheme(),
getLegend(),
kde2d(),
meltDistributionTable(),
modeSelektor(),
periodAnnotate(),
quantile2d(),
reverselog10_trans()