* QUESTION: How to replace missing values of bdifu1 TO bdifu20 by the mean * value (for the applicable sex) but only when (bmiss < 20). * Answer by rlevesque@videotron.ca. * Define dummy data file for illustration purposes. NEW file. INPUT PROGRAM. SET SEED=7654321. VECTOR bdifu(20F8.3). LOOP id=1 TO 50. LEAVE id. * about 50% of bmiss will be less than 20. COMPUTE bmiss=UNIFORM(40). COMPUTE sex=(UNIFORM(1)<.5). LOOP #id=1 TO 20. * about 10% of bdiful will be missing. IF (UNIFORM(1)<.9) bdifu(#id)=TRUNC(UNIFORM(5)+.5). END LOOP. END CASE. END LOOP. END FILE. END INPUT PROGRAM. EXECUTE. * Start the job. SORT CASES BY sex. aggregate outfile=bdifu.sav /presorted /break=sex /mbdifu1 to mbdifu20=mean(bdifu1 to bdifu20). match files file= * /table=bdifu.sav /by sex. do if (bmiss lt 20). + do repeat orig = bdifu1 to bdifu20 /copy=mbdifu1 to mbdifu20. + if (missing (orig)) orig=copy. + end repeat. end if. EXECUTE.