use subset of observations in SAS procedures

*Limiting Observations
* Read from a raw data file;
filename myfile 'c:\SASfiles\temp\myfile';
Data temp;
infile myfile obs=100;
input ...;
run;

*printing data;
proc print data=temp (obs=10);
proc print data=temp (firstobs=20 obs=50);

*copy to other data set;
data temp2;
set temp (obs=10);
... other statements...
run;

*frequency test;
proc freq data=temp (obs=50);
var ...your variables...
run;