How to set first observation to equal last observation

[novinosrin]

You really need tor review your SET statement dataset calls 

Play with some values to see distinct values 

proc sql;

select distinct rand_group

from have;

quit;



/*or a */

proc freq data=have;

tables rand_group;

run;

The above will give you an idea what's in your dataset to eventually know what to expect

[GS2]

This is the output from the proc freq of the data set I am using in the set statement

rand_group Frequency Percent Frequency Percent
Treatment A  27  50.94  27  50.94
Treatment B  26  49.06   53  100.00

Frequency Missing = 477

[novinosrin]

Ok so I suppose you got the same for 

Proc sql;

select distinct rand_group

from have

quit;

as well.

In that case , you are definitely not referencing the correct dataset that picks yes/no from mars or moon lol 

[GS2]

Proc sql;

select distinct rand_group

from SPIES.SPIES_ANALYSIS_DEMOS

quit;

proc freq data = SPIES.SPIES_ANALYSIS_DEMOS;

table rand_group;

run;

Both show only treatment group a and b

data SPIES_ANALYSIS_DEMOS2;
do _n_=1 by 1 until(last.study_id);
set SPIES.SPIES_ANALYSIS_DEMOS;
by study_id;
if _n_=2 then _temp=Rand_group;
end;
do _n_=1 to _n_;
set SPIES.SPIES_ANALYSIS_DEMOS;
by study_id;
if _n_=1 then Rand_group=_temp;
output;
end;
drop _:;
run;

I am setting it to the same data set that is showing only treatment a and b 

[novinosrin]

And is it still show YES, NO? 

If it does, can you check upstream thoroughly. And if it is not confidential that would violate security/compliance, can you attach your sas dataset here? So I can work on it

[GS2]

Still has a yes/no. I cannot release my data set. Thank you for the help but I am going to use an if/then statement and manually fill in the data.