Date:         Wed, 14 Dec 2011 13:43:38 -0500
Reply-To:     b miner <b_miner@LIVE.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         b miner <b_miner@LIVE.COM>
Subject:      Add Missing Records to Table and Impute Values of Last Non
              Missing.
Content-Type: text/plain; charset="iso-8859-1"

I have a dataset comprised of a group (G), a numeric value (x) and a sequential counter (within group) called s.

data test;

input G x s;

datalines;

1 1 1

1 2 2

1 . 3

2 . 1

2 1 2

3 1 1

3 2 2

3 . 1

3 . 1

4 1 1

4 2 2

4 3 3

4 4 4

;

run;

I want to first make sure each G has 4 records. So, G 1 would add 1 record with values . for x and 4 for s. G 2 would add two records (. and 3,4) etc.

Then, I want to scan the table and impute missing x values with the last non missing value for that group. So, for G 1 the missing value at s=1 will be a 2. 


Is there an easy way to do this - using arrays?