SAS IML Create combinations in a Hash Table

[Sanscrit_2prov]

Hi:

In SAS IML there is a function called ALLCOMB that can create a matrix of all possible combinations. This is a very helpful function but if the number of combinations is for n=large it doesn't work as well from an efficiency point of view. I was wondering if any one has created hash tables of all possible combinations to improve the efficiency. I know how to either use allcomb or do loops to create a matrix but instead I would like to create a Hash table lookup of the combinations in each row. Thanks   

[PeterClemmensen]

@Sanscrit_2prov welcome to the SAS Community 🙂 

Can you provide a small example of your problem and where it goes wrong?

[Ksharp]

Check GRAYCODE Function  in data step.

I would not think Hash could contain so many combinations. and it must be exploded .