sas entries manipulation

[jkf91]

save i have the following data:

Observation	x	y
1	1	2
2	3
3	2

as you can see, column y is not complete. BUT, all rows in column y should take the same value:

Observation	x	y
1	1	2
2	3	2
3	2	2

Two Questions:

First, I want to know how I can do that on SAS.

Next, I need want to keep observations such that x>=y. How can I do that?

Thanks,

C

[art297 · Accepted solution]

One way would be:

data want (drop=_:);

  set have (rename=(y=_y));

  retain y;

  if _n_ eq 1 then y=_y;

  if x gt y;

run;

[jkf91]

thanks a lot! that solved the problem!

just curious though....

what are these two doing?

drop=_:

rename=(y=_y)

thanks,

c

[art297]

Just a couple of shortcuts.  The rename statement changes the name of variable y, when the file is set, so that it will be seen to be variable _y;  I did it that way so that the later missing values of y wouldn't override the desired value from the first record.

The drop statement, then, just uses the semicolon as a wild card.  It says, in essence, to drop any variable that starts with an underscore (i.e., variable _y).

The semi colon has lots of under used useage in SAS as stated, nicely, in:

http://www2.sas.com/ proceedings/sugi29/054-29.pdf