topic Re: Store total number of records in a variable and select random sample in SAS Procedures

Store total number of records in a variable and select random sample

nicnad — Fri, 15 Mar 2013 16:01:30 GMT

Hi,

I would like to know how to store the number of records from a table in a variable and then based on that number select a random sample that is 10% of the size of the total number of records.

Here is what I came up with so far. My source table is cq_alert.closed_alert_cust :

data _NULL_;

if 0 then set cq_alert.closed_alert_cust nobs=n;

call symput('nrows',trim(left(put(n,8.))));

stop;

run;

%put nobs= int(&nrows/10); /* I'm trying to store 10% of my total number of records in variable nobs */

To illustrate this better, if my source table had 100 records, I would like to create a table with 10 random records from it.

Thank you for your help and time.

Re: Store total number of records in a variable and select random sample

data_null__ — Fri, 15 Mar 2013 16:12:42 GMT

Just use RATE=.1 with survelselect.

data h;
   do i = 1 to 100; 
      output; 
      end; 
   run; 
proc surveyselect data=h rate=.1 out=sample;
   run;

Re: Store total number of records in a variable and select random sample

nicnad — Fri, 15 Mar 2013 16:44:20 GMT

Thank you very much for the quick reply.

For the seconds part of my question :

Lets says I have this :

data _NULL_;

if 0 then set cq_alert.closed_alert_cust nobs=n;

call symput('nrows',trim(left(put(n,8.))));

stop;

run;

%put nobs= int(&nrows/10);

How do I use the variable nobs in a normal data procedure?

Re: Store total number of records in a variable and select random sample

data_null__ — Fri, 15 Mar 2013 17:08:47 GMT

You could create a macro variable NOBS with %LET or you could create the variable in your data step and use it in code as &nobs.

%let nobs= %sysevalF(&nrows/10,INTEGER);

Re: Store total number of records in a variable and select random sample

nicnad — Fri, 15 Mar 2013 17:11:43 GMT

Exactly what I needed.

Thank you very much for your help and time!