For each patient, keep only paired records by date and then do counts based on # of contiguous p

[WAL83]

Yes, I did not mean to mark that as accepted. Mouse malfunction...

[WAL83]

Your code IS resetting pair=1 but it deleted a record for some reason. Original dataset has 49 records, output dataset now has 48. Your code deletes the record in red... It was the last record for that ID and did not have a PAIR...

ID	Start_Date	Start_Time	End_Time	Value
2003	1-Jul-13	6:00:00	21:59:00	DAY
2003	1-Jul-13	22:00:00	5:59:00	NIGHT
2003	2-Jul-13	22:00:00	5:59:00	NIGHT
2003	3-Jul-13	6:00:00	21:59:00	DAY
2003	3-Jul-13	22:00:00	5:59:00	NIGHT
2003	4-Jul-13	6:00:00	21:59:00	DAY
2003	4-Jul-13	22:00:00	5:59:00	NIGHT
2003	5-Jul-13	6:00:00	21:59:00	DAY

[art297 · Accepted solution]

Indeed! I missed the case where it was the last.id and started with an otherwise potentially valid record. This code should correct for that:

data want (drop=_:);
  set have;
  by id;
  length action $6;
  retain _next_keep _last_kept_date _pair;
  if first.id then _pair=0;
  if not last.id then do;
    _next=_n_+1;
    set have (keep=start_date value
         rename=(start_date=_next_start
                 value=_next_value)) point=_next;
    if _next_keep='KEEP' then do;
      action='KEEP';
      _last_kept_date=start_date;
      pair=_pair;
      output;
      _next_keep='DELETE';
    end;
    else if start_date eq _next_start and
            value eq 'DAY' and
            _next_value eq 'NIGHT' then do;
      if 0<=(start_date-_last_kept_date)<=1 then _pair+1;
      else _pair=1;
      pair=_pair;
      action='KEEP';
      output;
      _next_keep='KEEP';
    end;
    else do;
      action='DELETE';
      output;
      _next_keep='DELETE';
    end;
  end;
  else do;
    if _next_keep eq 'KEEP' then do;
      action='KEEP';
      pair=_pair;
      output;
      _next_keep='DELETE';
    end;
    else do;
      action='DELETE';
      output;
      _next_keep='DELETE';
    end;
  end;
run;

Art, CEO, AnalystFinder.com

[WAL83]

Thanks for hanging in there!!! I realize what I was asking was not exactly clear at first. Will be more concise the next time. Thanks again!!!!