topic Re: Creating new variables from manifestations of a string variable in SAS Programming

Creating new variables from manifestations of a string variable

D1 — Mon, 18 Jan 2016 14:37:44 GMT

Hello everyone,

I’m new to SAS and have been trying to figure out how to solve the following problem:

Let’s assume I have the following dataset:

data specialty;

input ID specialty $12. ;

cards;

1 Neurologist

1 Psychologist

2 GP

3 Neurologist

4 Cardiologist

5 Cardiologist

;

run;

What I want to do now is to create a new column for every physician specialty from the column “specialty” and put a “1” in the respective column if it fits and zero otherwise.

So the result should look like this:

ID	specialty	Neurologist	Psychologist	GP	Cardiologist
1	Neurologist	1	0	0	0
1	Psychologist	0	1	0	0
2	GP	0	0	1	0
3	Neurologist	1	0	0	0
4	Cardiologist	0	0	0	1
5	Cardiologist	0	0	0	1

I solved the problem with creating every variable manually and lots of “if then statements” for now but I’m not very happy with this. Is there a more elaborated way to achieve the desired outcome?

Thank you!

Re: Creating new variables from manifestations of a string variable

Kurt_Bremser — Mon, 18 Jan 2016 15:01:47 GMT

data specialty;
input  ID  specialty $12. ;
x = 1;
cards;
1 Neurologist
1 Psychologist
2 GP
3 Neurologist
4 Cardiologist
5 Cardiologist
;
run;
proc transpose data=specialty out=wide (drop=_NAME_);
by ID;
id specialty;
var x;
run;

This basically provides what you wanted (having missing values instead of zero), but you only get 1 observation for ID=1, where both columns Neuroloigist and Psychologist have the value 1.

Re: Creating new variables from manifestations of a string variable

LinusH — Mon, 18 Jan 2016 15:04:12 GMT

Looks like a report to me. What is the intended use for the output data set?

I believe you can use cross tabulations in PROC FREQ for this.

Re: Creating new variables from manifestations of a string variable

RW9 — Mon, 18 Jan 2016 15:05:52 GMT

Well, this will give you what you want:

data specialty;
  input  ID  specialty $12. ;
  res=1;
  cards;
1 Neurologist
1 Psychologist
2 GP
3 Neurologist
4 Cardiologist
5 Cardiologist
;
run;

proc transpose data=specialty out=want;
  by id specialty;
  var res;
  id specialty;
  idlabel specialty;
run;

However I would advise against this approach, if you variables change then your going to need to reprogram. Its generally a good idea to have a general prefix and an incrementor so you can use arrays, you can still label them what ever your like, but its so much easier to code with:

data specialty;
  input  ID  specialty $12. ;
  res=1;
  cards;
1 Neurologist
1 Psychologist
2 GP
3 Neurologist
4 Cardiologist
5 Cardiologist
;
run;

data want;
  set specialty;
  array var{4} 8.;
  select(specialty);
    when ("Neurologist") var{1}=1;
    when ("Psychologist") var{2}=1;
    when ("GP") var{3}=1;
    when ("Cardiologist") var{4}=1;
    otherwise;
  end;
run;

You can then refer to the array of vars in further processing.

Re: Creating new variables from manifestations of a string variable

D1 — Mon, 18 Jan 2016 15:29:18 GMT

Thank you Kurt and RW9 for the quick responses. That is exactly what I needed!

Re: Creating new variables from manifestations of a string variable

Ksharp — Tue, 19 Jan 2016 02:30:15 GMT

data specialty;
input  ID  specialty $12. ;
x = 1;
n+1;
cards;
1 Neurologist
1 Psychologist
2 GP
3 Neurologist
4 Cardiologist
5 Cardiologist
;
run;
proc transpose data=specialty out=wide (drop=_NAME_ n);
by n;
id specialty;
var x;
copy id specialty;
run;
proc stdize data=wide out=want missing=0 reponly;run;