Dear All,
I have a dataset as below:
ID DATE EVENT
101 20Apr2021 Headache
101 21Apr2021 Nausea
101 20Apr2021 Headache
102 01May2021 Vomiting
102 02May2021 Vomiting
103 01Aug2021 Fatigue
104 01Aug2021 Fatigue
I need to flag the records where the observations in date and event column are same per each ID.
The output should be like the below:
ID DATE EVENT FLAG
101 20Apr2021 Headache Y
101 21Apr2021 Nausea
101 20Apr2021 Headache Y
102 01May2021 Vomiting
102 02May2021 Vomiting
103 01Aug2021 Fatigue
104 01Aug2021 Fatigue
Please help
One way
data have;
input ID DATE :date9. EVENT $;
format DATE date9.;
datalines;
101 20Apr2021 Headache
101 21Apr2021 Nausea
101 20Apr2021 Headache
102 01May2021 Vomiting
102 02May2021 Vomiting
103 01Aug2021 Fatigue
104 01Aug2021 Fatigue
;
data want(drop = c);
if _N_ = 1 then do;
dcl hash h();
h.definekey("ID", "DATE", "EVENT");
h.definedata("c");
h.definedone();
do until (z);
set have end = z;
if h.find() ne 0 then c = 1;
else c + 1;
h.replace();
end;
end;
set have;
if h.find() = 0 and c > 1 then flag = "Y";
run;
Result:
Obs ID DATE EVENT flag 1 101 20APR2021 Headache Y 2 101 21APR2021 Nausea 3 101 20APR2021 Headache Y 4 102 01MAY2021 Vomiting 5 102 02MAY2021 Vomiting 6 103 01AUG2021 Fatigue 7 104 01AUG2021 Fatigue
One way
data have;
input ID DATE :date9. EVENT $;
format DATE date9.;
datalines;
101 20Apr2021 Headache
101 21Apr2021 Nausea
101 20Apr2021 Headache
102 01May2021 Vomiting
102 02May2021 Vomiting
103 01Aug2021 Fatigue
104 01Aug2021 Fatigue
;
data want(drop = c);
if _N_ = 1 then do;
dcl hash h();
h.definekey("ID", "DATE", "EVENT");
h.definedata("c");
h.definedone();
do until (z);
set have end = z;
if h.find() ne 0 then c = 1;
else c + 1;
h.replace();
end;
end;
set have;
if h.find() = 0 and c > 1 then flag = "Y";
run;
Result:
Obs ID DATE EVENT flag 1 101 20APR2021 Headache Y 2 101 21APR2021 Nausea 3 101 20APR2021 Headache Y 4 102 01MAY2021 Vomiting 5 102 02MAY2021 Vomiting 6 103 01AUG2021 Fatigue 7 104 01AUG2021 Fatigue
This looks somewhat complex program. Hard for me to understand. Could you please help me with a simple easy to understand program ?
Hello @r3570,
@r3570 wrote:
This looks somewhat complex program. Hard for me to understand. Could you please help me with a simple easy to understand program ?
Maybe it's easier to understand if you split the task into several short steps:
/* Create a temporary unique sort key _SEQNO */
data _tmp / view=_tmp;
set have;
_seqno=_n_;
run;
/* Separate duplicate and unique ID-DATE-EVENT combinations */
proc sort data=_tmp out=dup nouniquekey uniqueout=uni;
by id date event;
run;
proc sort data=dup; by _seqno; run;
proc sort data=uni; by _seqno; run;
/* Reunite the two parts, flagging the duplicates */
data want(drop=_seqno);
set dup(in=d) uni;
by _seqno;
if d then flag='Y';
run;
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