topic Re: Flag next date after index date by group in SAS Programming

Flag next date after index date by group

MB_Analyst — Wed, 29 Apr 2020 17:31:38 GMT

I am trying to flag the date that is closet to the index date. My data looks like:

ID Index date

1 1 20MAR2020

1 0 21MAR2020

2 1 10APR2020

2 0 13APR2020

2 0 15APR2020

I would like to flag:

ID Index date close

1 1 20MAR2020 .

1 0 21MAR2020 1

2 1 10APR2020 .

2 0 13APR2020 1

2 0 15APR2020 0

Re: Flag next date after index date by group

PaigeMiller — Wed, 29 Apr 2020 17:37:37 GMT

data want;
    set have;
    prev_id=lag(id);
    prev_index=lag(index);
    if prev_id=id and prev_index=1 then close=1;
    else if prev_id=id and prev_index=0 then close=0;
run;

This assumes the data is sorted properly, and you are looking for next date after index as your title indicates and not closest date as your text indicates.