topic Re: Recoding multiple variables with three categories at once in SAS Programming

Recoding multiple variables with three categories at once

aowais — Wed, 16 Jan 2019 20:41:03 GMT

Hi,

I am trying to recode a number of variables with three categories 1=Yes, 2=No and 3=N/A as 1=Yes, 0=No and 3=. (i.e. missing). I've tried using the following code, but this changes both 2 and 3 to 0.

ARRAY VARS{5} g3_1 g3_2 g3_3 g3_4 g3_5;
DO _N_ = 1 TO 5;
IF VARS{_N_} NE 1 THEN VARS{_N_} = 0;
END;

Help please. Thanks!

Re: Recoding multiple variables with three categories at once

ChrisNZ — Wed, 16 Jan 2019 20:50:16 GMT

1. Do not write all upper case code, that's hard to read

2. This might help:

do I = 1 to 5;
  if VARS{I} =2 then VARS{I} = 0; 
  if VARS{I} =3 then VARS{I} = .;
end;

Re: Recoding multiple variables with three categories at once

ballardw — Wed, 16 Jan 2019 20:53:26 GMT

I have to assume that you mean you want to change the value of the variable from 2 to 0 and 3 to missing. Your code shows nothing about yes. no or n/a. If you have format that displays that text for the values you will need a different format.

data want;
   set have; 
   ARRAY VARS{5} g3_1 g3_2 g3_3 g3_4 g3_5;
   DO _N_ = 1 TO dim(vars);
      if vars[i]=2 then vars[i]=0;
      else if vars[i]=3 then vars[i]=.;
   END ;
run;

Re: Recoding multiple variables with three categories at once

aowais — Wed, 16 Jan 2019 20:59:37 GMT

Thank you. Point noted about upper case.

When I try your suggestion, it works for the first two variables, but for the last three, all values end up missing...

Re: Recoding multiple variables with three categories at once

ballardw — Wed, 16 Jan 2019 21:12:03 GMT

@aowais wrote:

Thank you. Point noted about upper case.

When I try your suggestion, it works for the first two variables, but for the last three, all values end up missing...

Example input and output data. This sounds like a data issue and you have not shared any actual values.

Also show your code. A common mistake is to use the code structure of

data have;

set have;

run;

The first pass through the data means that you have replaced the original values and are now further modifying the incorrectly coded values from the first pass through the data.

Does your log show any warnings?

Re: Recoding multiple variables with three categories at once

ChrisNZ — Wed, 16 Jan 2019 22:13:43 GMT

> it works for the first two variables, but for the last three, all values end up missing...

If the values are the same and the logic is the same, then the result is the same.

Check your data.

A more flexible logic might also help:

do I = 1 to 5;
  if      VARS{I} = 1 then ; 
  else if VARS{I} = 2 then VARS{I} = 0; 
  else                     VARS{I} = .;
end;

Re: Recoding multiple variables with three categories at once

aowais — Fri, 18 Jan 2019 14:17:58 GMT

Thank you! This worked!