Possibly unrelated Question :
I have 2 column variables : Id (character) and Disease (categorical, 12 different categories)
Each Id may have more than 1 Disease observation, which are ordered by Id.

I wish to create a 12x12 matrix for the categorical variable (Disease), in order to cross-tabulate the different diseases.
Ie. display the co-occurance of diseases by participant as a sort of binplot/heatmap/cross-tabulation...
The desired matrix would have x = Disease AND y = Disease

May I ask how I would go about this using SAS ?
Many thanks