Hi, my question is how to pick only consecutive 3 “Y” observations using SAS.

data s;

input id$ flag$ date;

cards;

A Y 12/04/1990

A Y 13/05/1989

A N 14/05/1989

A Y 21/05/1990

A N 23/06/1990

B N 12/04/1990

B Y 13/06/1989 } Y

B Y 14/09/1989 } Y

B Y 21/10/1990 } Y

B Y 23/01/1990

C N 12/02/1990

C Y 13/05/1989

C Y 14/11/1989

C Y 21/01/1990

C N 23/04/1990

;

run;

i want only the observations which is marked with parentheses, which is three consecutive Y values im done with few steps but stuck at last step, help the needful

data ss;

set s;

flagdown=lag(flag);

run;

the above program gives me the answer if i write a code like " If flag=“Y” and flagdown=“Y” ;" but ill get all the values with A B C, but i want pick only consecutive 3 observations with B…

help the needful…

Thanks & Regards;