Create flag for policy renewal within 365 days

[SBRVamsi]

The data looks like as below
I need a new flag like this as Renewal

My logic is

Policy_no =lag(policy_no) and start_date=lag(start_date)>=365 then Renewal='R1'

But my question if he renews it again in the next year it should be R2, and so on for huge data

So I need my Renewal flag like this ...as below

Policy_no. Start_date. Renewal
10100. 03Jan2014. N
10100. 07Mar2015. R1
10100. 10Sep2016. R2
21001. 15Mar2014. N
21001. 15Mar2014. N
21001. 20Oct2015. R1

I need a renewal like this and my logic is like above. Please help me on this asap.

If need further information please reply me.

[SBRVamsi]

Sorry in he logic it should be
Policy_no =lag(policy_no) and
start_date-lag(start_date)>=365 then Renewal='R1'

It's minus symbol after start_date

[SBRVamsi]

The data looks like as below
I need a new flag like this as Renewal

My logic is

Policy_no =lag(policy_no) and
start_date-lag(start_date)>=365 then Renewal='R1'

But my question if he renews it again in the next year it should be R2, and so on for huge data

So I need my Renewal flag like this ...as below

Policy_no. Start_date. Renewal
10100. 03Jan2014. N
10100. 07Mar2015. R1
10100. 10Sep2016. R2
21001. 15Mar2014. N
21001. 15Mar2014. N
21001. 20Oct2015. R1

I need a renewal like this and my logic is like above. Please help me on this asap.

If need further information please reply me.

[PGStats]

Use a do until() and logic

data want;
do until(last.policy_no);
    set have; by policy_no;
    renewal = "N  ";
    if missing(last_date) then last_date = start_date;
    else if intck("DAY", last_date, start_date) >= 365 then do;
        r = sum(r, 1);
        renewal = cats("R", r);
        last_date = start_date;
        end;
    output;
    end;
drop last_date r;
run;

[Reeza · Accepted solution]

You're on the right path. 

Rather than use lag to check for the same policy number use BY group processing. 

LAG doesn't operate conditionally so calculate the value ahead of time and store that in a variable to use in your calculation. 

What happens if renewal is <365 days? That case isn't covered in your logic. 

Heres a sample(untested) that should get you started. 

By policy_no;

Retain index;

prev_start=lag(start_date;

if first.policy_no then do;

    Prev_start=.;

    Index=0;

    Renewal = 'N';

end;

Else if stsrt_date - prev_start >= 365 then do;

Renewal =catt('R', index);

end;

else <logic?>;

index+1;

[Ksharp]

data have;
infile cards dlm='. ';
input Policy_no Start_date : date9. Renewal $;
format start_date date9.;
cards;
10100. 03Jan2014. N
10100. 07Mar2015. R1
10100. 10Sep2016. R2
21001. 15Mar2014. N
21001. 15Mar2014. N
21001. 20Oct2015. R1
;
run;
data want;
 set have;
 by policy_no;
 length new $ 20;
 new='N';
 if first.policy_no then count=0;
 if dif(start_date) ge 365 and not first.policy_no then do;
  count+1;new=cats('R',count);
 end;
 drop count;
run;

[SBRVamsi]

Thanks a lot ksharp...

[SBRVamsi]

Thank you Guru