Copy values to entire section

[bharath86]

Hi,

I have a simple problem to solve, 'dy' variable has samevalue for an entire section however it is missing in few rows under each section. I would like to copy the blanks with 'dy' value of that section. How can we do that without writing any loops in a simple code line. Please advise. 

data test ;
input section dy ;
datalines;
1 .
1 .
1 .
1 33
1 33
1 33
1 33
1 .
1 .
1 .
2 44
2 44
2 44
2 .
2 .
2 .
2 44
2 44
;
run;

section	dy	desired_dy
1	.	33
1	.	33
1	.	33
1	33	33
1	33	33
1	33	33
1	33	33
1		33
1		33
1		33
2	44	44
2	44	44
2	44	44
2	.	44
2	.	44
2	.	44
2	44	44
2	44	44

Thank you

[novinosrin]

data test ;
input section dy ;
datalines;
1 .
1 .
1 .
1 33
1 33
1 33
1 33
1 .
1 .
1 .
2 44
2 44
2 44
2 .
2 .
2 .
2 44
2 44
;
run;


data want;
 merge test test(rename=(dy=desired_dy) where=(desired_dy ne .));
 by section;
run;

[r_behata · Accepted solution]

data test ;
input section dy ;
datalines;
1 .
1 .
1 .
1 33
1 33
1 33
1 33
1 .
1 .
1 .
2 44
2 44
2 44
2 .
2 .
2 .
2 44
2 44
;
run;


proc sort data=test;
	by section descending dy ;
run;

data want;
	update test(obs=0) test;
	by section;
	output;
run;