CONDITIONALLY DELETING FIRST OBSERVATION

[d6k5d3]

For this I have already looked at the posts in the community, but they seemed to not serve my purpose. I tried the following code, which did not work.

data zzz; 
set yyy; 
by return notsorted; 
if Day= "Sun" and first.return then delete; 
run;

 I have the following table:

Date      Time       Day      Return

03/05    12:20       Sun     2.45

03/05    12:30       Sun     3.23

03/05    12:35       Sun     2.03

03/05    12:40       Sun     2.55

03/05    12:45       Sun     3.11

03/05    12:50       Sun     2.67

03/06    12:25       Mon     2.99

03/06    12:30       Mon     3.09

03/06    12:35       Mon     2.05

03/06    12:40       Mon     2.61

03/06    12:45       Mon     3.32

03/06    12:50       Mon     2.39

...

...

...

03/12    12:20       Sun     2.92

03/12    12:30       Sun     3.13

03/12    12:35       Sun     2.63

03/12    12:40       Sun     2.15

03/12    12:45       Sun     3.51

03/12    12:50       Sun     2.57

I want to delete the first observation of each Sunday. What was wrong with my code? A lot more than expected rows got deleted. 52 Sundays in a year times 12 years = 624 observations are supposed to be deleted.

[Tom · Accepted solution]

Sounds like you want FIRST.DAY instead of FIRST.RETURN.  Since you have mulitple values or RETURN for each value of DAY the flag FIRST.RETURN could will be true multiple times on a Sunday. But FIRST.DAY will be true only for the first record for that day.

[d6k5d3]

Thanks a lot! Yes, that makes sense. What a stupid SAS beginner I am! 😄

[PeterClemmensen]

@d6k5d3, far from stupid asking questions in here 😉 Welcome to the SAS communities.