如何得到特定观测的个数

shiyiming

如题，数据集中要得到同一个ID的观测条数

shiyiming

[code:jdwv9zsz]data a;
input no $ singn;
datalines;
s1 1
s1 1
s1 2
s2 1
s2 2
s2 2
s3 1
s3 1
s4 2
s4 2
;
proc sql;
select no,count(no) as contno  from a group by no;
select no,singn,count(no and singn) as contsn from a group by no,singn;
quit;[/code:jdwv9zsz]

shiyiming

是不是只要count有观测数值的obs就可以了？

proc means data=aa noprint;
        by no;
        var sign;
        output out=count(drop=_type_ _freq_) N=/autoname;
run;