topic Re: Generate all permutations list - 2 levels in SAS Programming

Generate all permutations list - 2 levels

brulard — Tue, 08 May 2018 17:03:51 GMT

hi,

Can someone suggest an approach to list all permutations for:

Re: Generate all permutations list - 2 levels

Reeza — Tue, 08 May 2018 17:11:12 GMT

If you have IML this becomes trivial, see the example here:

https://blogs.sas.com/content/iml/2013/09/30/generate-combinations-in-sas.html

If you don't have IML you can use CALL ALLCOMB or you do a SQL join.

data have;
input name $;
cards;
A
B
C
;
run;

proc sql;
create table want as
select catx("-", t1.name, t2.name, t3.name) as want
from have as t1
cross join have as t2
cross join have as t3;
quit;

Re: Generate all permutations list - 2 levels

PaigeMiller — Tue, 08 May 2018 17:15:50 GMT

Also trivial using Cartesian join in PROC SQL

data r;
    input r;
    cards;
1
2
;
run;

/* Repeat to create data sets C and U */

proc sql;
    create table want as select * from r,c,u;
quit;

Re: Generate all permutations list - 2 levels

PaigeMiller — Tue, 08 May 2018 17:21:28 GMT

Also can be done in PROC FACTEX

Re: Generate all permutations list - 2 levels

brulard — Tue, 08 May 2018 17:32:20 GMT

Thanks for the tip, hi, i could consider IML in Unix (aix) sas as it is running. I'll read this link to learn how to output it to a dataset https://blogs.sas.com/content/iml/2011/04/18/writing-data-from-a-matrix-to-a-sas-data-set.html

Re: Generate all permutations list - 2 levels

brulard — Tue, 08 May 2018 19:19:31 GMT

thanks for ur tip to create 3 tables... In order to ultimately arrive to 1 column output table, had to add a few lines . (there is likely a more efficient way of doing it 🙂 )

data r;
    input r0;
    cards;
1
2
3
;
run;

/* Repeat to create data sets C and U */

data c;
    input c0;
    cards;
1
2
3
;
run;

data u;
    input u0;
    cards;
1
2
3
;
run;

proc sql;
    create table want as select * from r,c,u;
quit;

/*convert to char var */

data want2;
format r c u $1.;
set want;
r=left(put(r0,best.));
c=left(put(c0,best.));
u=left(put(u0,best.));
run;

/* use trim with char vars  to produce output as one column */

proc sql; create table wantFIN as 
select trim('R'||r||'C'||c||'U'||u) as NEWVAR
from want2;
quit;

Re: Generate all permutations list - 2 levels

PaigeMiller — Tue, 08 May 2018 19:37:29 GMT

Much simpler:

data r;
    input r $;
    cards;
R1
R2
R3
;
run;
 /* repeat for data sets C and U */
proc sql;
    select cats(r,c,u) from r,c,u;
    /* ALTERNATIVE: select catx('-',r,c,u) from r,c,u; */
quit;

Re: Generate all permutations list - 2 levels

brulard — Tue, 08 May 2018 19:39:48 GMT

... learning everyday , thanks!

Possibility	Permutations
1	R1-C1-U1
2	R1-C1-U2
3	R1-C2-U2
4	R1-C2-U3
5	R2-C2-U2
ETC.	…