Ordering the axis labels in geom_tile

Question

I have a data frame containing order data for each of 20+ products from each of 20+ countries. I have put it in a highlight table using ggplot2 with code simila

Answer 1

maybe this StackOverflow question can help:

Order data inside a geom_tile

specifically the first answer by Brandon Bertelsen:

"Note it's not an ordered factor, it's a factor in the right order"

It helped me to get the right order of the y-axis in a ggplot2 geom_tile plot.

Answer 2

As smillig says, the default is already to order the axes alphabetically, but the y axis will be ordered from the lower left corner up.

The basic rule with ggplot2 that applies to almost anything that you want in a specific order is:

• If you want something to appear in a particular order, you must make the corresponding variable a factor, with the levels sorted in your desired order.

In this case, all you should need to do it this:

mymelt$variable <- with(mymelt,factor(variable,levels = rev(sort(unique(variable)))))

which should work regardless of whether you're running R with stringsAsFactors = TRUE or FALSE.

This principle applies to ordering axis labels, ordering bars, ordering segments within bars, ordering facets, etc.

For continuous variables there is a convenient scale_*_reverse() but apparently not for discrete variables, which would be a nice addition, I think.

Answer 3

Another possibility is to use fct_reorder from forecast library.

library(forecast)
mydf %>%
pivot_longer(cols=c('all regions', 'americas', 'europe')) %>% 
  mutate(name1=fct_reorder(name, value, .desc=FALSE)) %>% 
  ggplot( aes(x = industry, y = name1, fill = value)) +
  geom_tile() + geom_text(aes( label = value))

Answer 4

The y-axis on your chart is also already ordered alphabetically, but from the origin. I think you can achieve the order of the axes that you want by using xlim and ylim. For example:

ggplot(mymelt, aes(x = industry, y = variable, fill = value)) +
    geom_tile() + geom_text(aes(fill = mymelt$value, label = mymelt$value)) +
    ylim(rev(levels(mymelt$variable))) + xlim(levels(mymelt$industry))

will order the y-axis from all regions at the top, followed by americas, and then europe at the bottom (which is reverse alphabetical order, technically). The x-axis is alphabetically ordered from all industries to steel with cars in between.

Answer 5

Maybe a little bit late,

with(mymelt,factor(variable,levels = rev(sort(unique(variable)))))

this function doesn't order, because you are ordering "variable" that has no order (it's an unordered factor).

You should transform first the variable to a character, with the as.character function, like so:

with(mymelt,factor(variable,levels = rev(sort(unique(as.character(variable))))))