topic Re: is it possible to grab an observation and its upper row? in SAS Programming

is it possible to grab an observation and its upper row?

harrylui — Thu, 20 Feb 2020 09:37:53 GMT

hi all,

encounter a problem. is it possible to grab an observation and its upper row together?

for example, if i want to draw out harry and peter.

Name Good student

Ben

Peter

Harry Y

Alice

is it always one way to do it like following code?

data want;

set have;

if name in ("peter" , "harry");

run;

can i write a program with designed pattern like

Extract data which name is harry and N-2 observation

and the output should like this:

Name Good student

Ben

Harry Y

thanks in advance

Harry

Re: is it possible to grab an observation and its upper row?

Satish_Parida — Thu, 20 Feb 2020 09:43:33 GMT

There is a function called LAG can be used in your situation. Can you please give a better example and also explain if the GOOD STUDENT flag affecting your selection. This example is not clear enough.

Re: is it possible to grab an observation and its upper row?

PeterClemmensen — Thu, 20 Feb 2020 09:47:35 GMT

Do you want to look for Harry or any good student? He may not be the only one 🙂

Re: is it possible to grab an observation and its upper row?

yabwon — Thu, 20 Feb 2020 10:44:40 GMT

Hi,

for your setup I would consider something like that:

data have;
infile cards missover;
input Name $ Good_student $ 1.;
cards;
Ben
Peter
Harry Y
Alice
;
run;

data want;
  set have curobs=curobs;
  if Good_student = "Y" then
    do point = max(curobs-1,1) to curobs;
      set have point=point;
      output;
    end;
run;
proc print;
run;

but it doesn't cover situations when you have for example two consecutive "good students", i.e. "Y" in row N and N+1.

All the best

Bart

Re: is it possible to grab an observation and its upper row?

harrylui — Tue, 25 Feb 2020 10:58:46 GMT

THANKS this is what i need