Hello,
I'm looking for an efficient way to create dummy variables and I've seen this example online:
DATA auto ; LENGTH make $ 20 ; INPUT make $ 1-17 price mpg rep78 ; CARDS; AMC Concord 4099 22 3 AMC Pacer 4749 17 3 Audi 5000 9690 17 5 Audi Fox 6295 23 3 BMW 320i 9735 25 4 Buick Century 4816 20 3 Buick Electra 7827 15 4 Buick LeSabre 5788 18 3 Cad. Eldorado 14500 14 2 Olds Starfire 4195 24 1 Olds Toronado 10371 16 3 Plym. Volare 4060 18 2 Pont. Catalina 5798 18 4 Pont. Firebird 4934 18 1 Pont. Grand Prix 5222 19 3 Pont. Le Mans 4723 19 3 ; RUN;
DATA auto2; set auto; ARRAY dummys {*} 3. rep78_1 - rep78_5; DO i=1 TO 5; dummys(i) = 0; END; dummys( rep78 ) = 1; RUN;
This has been working for me except when I have missing values (e.g. if rep78 has missing values). Is there a way to adjust this code to account for the missing values or do I need a different solution?
Thanks
DATA auto2;
set auto;
ARRAY dummys rep78_1 - rep78_5 (5*0);
if not missing(rep78) then dummys( rep78 ) = 1;
RUN;
This gives your dummy variables a value of zero when rep78 is missing. You can modify that further to give the dummy variables a missing value as well.
DATA auto2;
set auto;
ARRAY dummys rep78_1 - rep78_5 (5*0);
if not missing(rep78) then dummys( rep78 ) = 1;
RUN;
This gives your dummy variables a value of zero when rep78 is missing. You can modify that further to give the dummy variables a missing value as well.
Hello,
You mentioned that 'You can modify that further to give the dummy variables a missing value as well.' Can you show me that modification?
Thank you.
Replace the 0 with a .
Make sure the value of REP78 is something you could use as an index into the array.
if rep78 in (1:5) then dummys( rep78 ) = 1;
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