Stack variables by another variable

[Greg Saldutte]

Hello,

I previously posted a thread about stacking variables. See here: https://www.statalist.org/forums/for...ange-of-values

I cannot post the data, so I use the example of people being surveyed on their two favorite foods. The data looks like this:

ID fav1 fav2 gender
1 pizza burger 0
2 burger pizza 1
3 steak burger 1
4 burger steak 0

The fav1 and fav2 variables would be stacked into one variable this way:

stack fav1 fav2, into(fav)

A bar graph of this would be created:

graph bar (count), over(fav)

In addition to a normal bar graph, I would like to do separate bar graphs by gender. Is there a way to preserve the gender variable through the stack, in order to later create two separate bar graphs by gender?

[Nick Cox]

Your previous thread was here https://www.statalist.org/forums/for...ange-of-values ; please give a cross-reference so that people can find it easily.

Similarly, in that thread I re-engineered your data example as input code and doing that is a good idea.

What you want is a small extension of the previous answer

clear 
input ID str6(fav1 fav2) gender 
1 pizza burger 1
2 burger pizza 0 
3 steak burger 0 
4 burger steak 1
end 

stack fav1 gender fav2 gender, into(fav gender)  
graph bar (count), over(fav) over(gender)

The help for stack does give examples of repeating variables in this way.

[Marcos Almeida]

I'm wondering why not just use the if qualifier for separate graphs, or addding - over(sex) - for a separate display on the same graph.

P.S.: Crossed with Nick's insightful reply. My suggestion was exactly his second line code.

[Greg Saldutte]

Thank you both. The problem is now solved.