There are two ways to select specific observations in
a SAS data set when you create a new SAS data set:
Delete the observations
that do not meet a condition, keeping only the ones that you want.
Accept only the observations
that meet a condition.
To delete an observation,
first identify it with an IF condition, and then use a DELETE statement
in the THEN clause:
IF condition THEN
Processing the DELETE statement for an observation causes SAS to return immediately to the beginning of the DATA step for a new observation without writing the current observation to the output DATA set. The DELETE statement does not include the observation ...