Retain and augment value basis criteria and event

[bnarang]

Hi

I am trying to work around a certain business problem where I need to flag certain event. I have tried coding but unable to come to any solution being a novice. Any help will be appreciated.

For the simplicity purposes, consider the data below. I have two fields ID and event with ID as identifier and event as specific event either a or b

Value to move and augment in set. for example - for first set of a ( which are 3 obs. for ID1) as 0

Value to change to 1 when event b occurs and remains for set in continuation

Value to change to 2 when event changes again and to a

Value to change to 3 when event change again to b

Value should initialize to 0 post 3 events in event a

Input:

ID event

1     a

1     a

1     a

1     b

1     b

1     a

1     a

1     b

1     a

1     a

2     a

2     b

2     a

2     a

2     b

Output:

ID event  Value

1     a        0

1     a        0

1     a        0

1     b        1

1     b        1

1     a        2

1     a        2

1     b        3

1     a        0

1     a        0

2     a        0

2     b        1

2     a        2

2     a        2

2     b        3

Thanks in Advance

[Astounding · Accepted solution]

Worth trying:

data want;

set have;

by id event notsorted;

if first.id then value=0;

else if first.event then value + 1;

if value=4 then value=0;

run;

[bnarang]

Thanks. The solution has worked.