outputing a frequency count of 0

[BenBrady]

I have made a variable called age_group which has been dervied from an existing variable age. the variable age_group is split up as follows:

age_group=1 if age<35

age_group=2 if  35<=age<=75

age_group=3 if age>75.

When I run a proc freq on the data, age_group=3 does not appear in the output table because there are 0 observations of this in the data. I am wandering how I can get the proc freq to display a frequency of 0 for age_group=3.

Thanks

[PeterClemmensen]

Check out this solution

https://communities.sas.com/t5/SAS-Procedures/PROC-FREQ-Include-Zero-Counts/td-p/325505

[ChrisNZ]

proc freq does not have an easy option for this, but proc means does. Do you need proc freq?

data CLASSES; 
  AGE=30; output; 
  AGE=60; output; 
  AGE=90; output; 
data HAVE; 
  AGE=60; output; 
  AGE=90; output; 
proc means data=HAVE classdata=CLASSES nway;
   class AGE;
   output out=FREQ;
run; 

AGE	N Obs
30	0
60	1
90	1

[BenBrady]

yes I do need to use proc freq

[RW9 · Accepted solution]

Why do you need to use proc freq?  Proc freq provides counts of data which is present.  In most scenarios where I have to do this, then I merge the results back to the distinct list of options:

proc sql;
  create table WANT as
  select  COALESCE(A.AGE_GROUP,B.AGE_GROUP) as AGE_GROUP,
          case when B.N=. then 0 else B.N end as N
  from    (select distinct AGE_GROUP from HAVE) A
  full join MEANS_OUTPUT B
  on      A.AGE_GROUP=B.AGE_GROUP;
quit;

However, if you use the right procedure, proc means, then you can use nway (and also multi-label formats if you need to combinations and such like) and do it in one proc means step.