Fill in the blanks with the previous value

[sweetgorgor]

Portfolio	Value	New_Value
A	2	2
A	3	3
A		3
A		3
B	2	2
B	2	2
B		2

Hi, I have a table with the  first 2 columns (Portfolio, Value) where I want to create a 3rd column to fill in all the blanks with the previous (Latest value), by portfolio. Essentially I am trying to derive column 3. I tried to use Lag and retain in a data step I can't seem to get it to work. can someone help?

Thanks!

[Mit · Accepted solution]

data have;
input portfolio $ value;
cards;
A 2
A 3
A 
A 
B 2
B 
B 
B 4
B 
B 
,
run;

proc sort data=have ;
by portfolio;
run;

data want;
set have;
by portfolio;
retain new_value;
if not missing(value) then new_value=value;
run;

portfolio	value	new_value
A	2	2
A	3	3
A		3
B	2	2
B		2
B	4	4
B		4

[sam369]

Hi,

another apporach, i used Mit Have dataset

data have;

input portfolio : $1. value;

cards;

A 2

A 3

A 

A 

B 2

B 

B 

B 4

B 

B 

;

run;

data want;

do until(last.portfolio);

set have;

by portfolio notsorted;

new_val=ifn(value ne .,value,new_val);

output;

end;

run;

Thanks

Sam

[sweetgorgor]

Thanks guys! I used Mit's and it worked like a charm! Sam yours also works! Thank you!