topic Re: Check for special values in numbered range lists in SAS Programming

Check for special values in numbered range lists

Georg_UPB — Wed, 02 Apr 2014 07:34:21 GMT

Hi everyone,

I've used numbered range lists to input variables and to check them for missing values, which worked quite well: If nmiss(of a1-a3 b1-b3)>0 Then...

Now, I need to also check if any of the variables is zero. Therefore, I enhanced the If-clause accordingly: If nmiss(of a1-a3 b1-b3)>0 or min(of a1-a3 b1-b3)=0 Then...

Interestingly, this slows down processing time considerably (on my machine for >60 variables). Although I can live with that, I wonder if there's a better approach.

Data zzz;

Input a1-a3 b1-b3;

If nmiss(of a1-a3 b1-b3)=0 And min(of a1-a3 b1-b3)>0 Then Output;

Datalines;

1 2 3 4 5 6

1 . 3 4 5 6

1 2 3 4 0 6

;

Run;

Re: Check for special values in numbered range lists

RW9 — Wed, 02 Apr 2014 08:53:39 GMT

You could consider normalizing your data, so something like:

Section Type Value

1 A1 1

1 A2 2

...

3 B3 6

Then you could use SQL to sum and find missing values. This may help with performance, however the secondary benefit of this is scalability. So you have >60 variables at the moment, this is 60 rows per group, however what about 120, or more. As for your example, I couldn't see any way of speeding it up other than that.

Re: Check for special values in numbered range lists

LinusH — Wed, 02 Apr 2014 09:04:55 GMT

If your source data is in SAS tables, and if you want to subset your data with this condition, use WHERE instead,

Otherwise, I can't see any real alternative. Syntactically you could use an array instead, but it's very unlikely that it could be more efficient than built-in functions.

Re: Check for special values in numbered range lists

Haikuo — Wed, 02 Apr 2014 09:27:59 GMT

Not sure if it makes any difference, but you may try to replace two functions with only one "ORDINAL",

Data zzz;

Input a1-a3 b1-b3;

/* If nmiss(of a1-a3 b1-b3)=0 And min(of a1-a3 b1-b3)>0;*/

if ordinal(1,of a1-a3 b1-b3) >0;

Datalines;

1 2 3 4 5 6

1 . 3 4 5 6

1 2 3 4 0 6

;

Run;

Haikuo

Re: Check for special values in numbered range lists

data_null__ — Wed, 02 Apr 2014 09:38:48 GMT

Maybe it will be a bit faster if you split the expressions into two subsetting IFs. This way MIN is only executed for observations that have no missing values.

Data zzz2;
   Input a1-a3 b1-b3;
   If nmiss(of a1-a3 b1-b3) eq 0; 
   if min(of a1-a3 b1-b3) gt 0; 
   Datalines; 
1 2 3 4 5 6
1 . 3 4 5 6
1 2 3 4 0 6
;;;;
   Run;