Sort by (total) bar height of stacked bar chart

[William Blackmon]

Basic question but I'm struggling. Title basically says it all. How do you order a stacked bar chart by the total heights of the bars?

Basic example:

sysuse auto, clear
gen category = mod(_n,3)
replace category = 3 in 3/6
graph hbar (count), over(foreign) over(category) asyvars stack

[Andrew Musau]

graph hbar (count), over(foreign) over(category, sort(1)) asyvars stack

[William Blackmon]

This sorts by the first category of, in this case, foreign. Not the bar total. (Realize now that my example doesn't demonstrate this well.)

[Andrew Musau]

Install labmask from the Stata Journal, by Nick Cox and sort the categories by frequency, create groups and label these by their category names.

search labmask

sysuse auto, clear
gen category = mod(_n,3)
replace category = 3 in 3/6
bys category: gen count=_N
egen total= group(count category)
labmask total, val(category)
graph hbar (count), over(foreign) over(total) asyvars stack

[William Blackmon]

Thanks again Andrew, appreciate it. This works! Seems odd to me that there isn't a more direct way of doing this using the graph syntax, but this workaround is great.

[Nick Cox]

Here's a way to do it a little more directly. The logic is really the same as that of Andrew Musau.

sysuse auto, clear
gen category = mod(_n,3)
replace category = 3 in 3/6

myaxis total = category, sort(count)
graph hbar (count), over(foreign) over(total) asyvars stack

https://www.statalist.org/forums/for...e-or-graph-use explains about myaxis -- on which also see Stata Journal 21(3) (in press at the time of writing).

As for why this isn't easier: I think the logic of graph hbar is that stacking follows calculations, and not the other way round. Coding could be otherwise, but it isn't.