grouped barplot: order x-axis & keep constant bar width, in case of missing levels

Question

Here is my script (example inspired from here and using the reorder option from here):

library(ggplot2)
Animals <- read.table(
  header=TRUE, tex         


        

Answer 1

Along the same lines as the answer from user Alex, a less manual way of adding the categories might be

d <- with(Animals, expand.grid(unique(Category), unique(Reason)))
names(d) <- names(Animals)[1:2]
Animals <- merge(d, Animals, all.x=TRUE)
Animals$Species[is.na(Animals$Species)] <- 0