How to read data from next line?

[Gothardt]

I have a dataset that looks like this:

Obs	ID	Indate	Outdate	Lines
1	1	17/08/10	20/08/10	1
2	1	17/08/10	22/08/10	2
3	2	06/01/11	10/01/11	1
4	3	15/08/10	15/08/10	1
5	3	15/08/10	17/08/10	2
6	3	15/08/10	25/08/10	3
7	3	15/08/10	21/09/10	4
8	4	17/06/12	17/06/12	1
9	5	26/01/11	27/01/11	1
10	6	06/11/12	06/11/12	1
11	6	14/12/12	14/12/12	1
12	6	17/11/14	17/11/14	1
13	6	17/11/14	18/11/14	1
14	7	30/10/10	31/10/10	1
15	7	30/10/10	01/11/10	2

And by using the statement:

proc sort data=have;

     by pnr indate;

run;

data have;

     set have; by pnr indate;

     LastLine=last.indate;

run;

I get this:

Obs	ID	Indate	Outdate	Lines	LastLine
1	1	17/08/10	20/08/10	1	0
2	1	17/08/10	22/08/10	2	1
3	2	06/01/11	10/01/11	1	1
4	3	15/08/10	15/08/10	1	0
5	3	15/08/10	17/08/10	2	0
6	3	15/08/10	25/08/10	3	0
7	3	15/08/10	21/09/10	4	1
8	4	17/06/12	17/06/12	1	1
9	5	26/01/11	27/01/11	1	1
10	6	06/11/12	06/11/12	1	1
11	6	14/12/12	14/12/12	1	1
12	6	17/11/14	17/11/14	1	0
13	6	17/11/14	18/11/14	1	1
14	7	30/10/10	31/10/10	1	0
15	7	30/10/10	01/11/10	2	1

It is correct until observation nr. 12. This should be 1 because Lines=1 in the next row... I've tried to sort by Outdate instead and I have used the lag(indate) but nothings works for me... How do I get it right? 

[RW9]

Your code doesn't use lines at all it is just flagging the last indate.  Sort by all of the items in the group, and then use last.smallest group, for example (not tested as test data not as datastep):

proc sort data=have;
  by pnr indate lines;
run;
 
data have;
  set have; 
  by pnr indate lines;
  lastline=last.lines;
run;

[Gothardt]

I've already tried this and it dose not work: all the values of last.line =1...

[data_null__ · Accepted solution]

Use a view and create a new variable G(roup) that is incremented when lines eq 1.

data inout;
   infile cards dsd dlm='09'x firstobs=2;
   input id (indate outdate)(:ddmmyy.) lines;
   format indate outdate ddmmyy10.;
   cards;
ID	Indate	Outdate	Lines
1	17/08/10	20/08/10	1
1	17/08/10	22/08/10	2
2	6/1/2011	10/1/2011	1
3	15/08/10	15/08/10	1
3	15/08/10	17/08/10	2
3	15/08/10	25/08/10	3
3	15/08/10	21/09/10	4
4	17/06/12	17/06/12	1
5	26/01/11	27/01/11	1
6	6/11/2012	6/11/2012	1
6	14/12/12	14/12/12	1
6	17/11/14	17/11/14	1
6	17/11/14	18/11/14	1
7	30/10/10	31/10/10	1
7	30/10/10	1/11/2010	2
;;;;
   run;
proc print;
   run;
data inout2v / view=inout2v;
   set inout;
   by id;
   if first.id then g=0;
   if lines eq 1 then g+1;
   run;
data inout2;
   set inout2v;
   by id g;
   last = last.g;
   run;
proc print;
   run;

[Gothardt]

This datastep dosen't work:

data inout2;
   set inout2;
   by id g;
   last = last.g;
   run;
proc print;

I get: 

ERROR: BY variable pnr is not on input data set

ERROR: BY variable is not on input data set

[Gothardt]

I found out - it seems to work without the view-statement. Thanks a lot!

[data_null__]

I changed to the view after I had use a data set.  The perils of a continuing SAS session.  I'll edit my reply.