Deleting observations based on other observations

[RTN]

Hi

I need help deleting observations based on other observations using SAS 9.4.

I have a number of people with an ID-number a year and a score from that year.

I would like to keep the first observation for one person everytime the score changes, also if the person has had that score before. I want to delete subsequent scores that are the same. Can someone help me with that?

data have;

input id year score;

1 2000 0

1 2002 1

1 2003 1

1 2004 0

2 2000 0

2 2003 0

3 2001 2

3 2003 4

3 2006 3

3 2007 3

;

run;

What I want:

1 2000 0

1 2002 1

1 2004 0

2 2000 0

3 2001 2

3 2003 4

3 2007 3

Thank you in advance.

Regards,

RTN

[novinosrin · Accepted solution]

HI @RTN  Do you mean this?

data have;

input id year score;
cards;
1 2000 0
1 2002 1
1 2003 1
1 2004 0
2 2000 0
2 2003 0
3 2001 2
3 2003 4
3 2006 3
3 2007 3
;

data want;
set have;
by id score notsorted;
if first.score;
run;

[RTN]

Yes thank you!
That works perfectly.