s*********h
发帖数: 6288 | 1 I want to select randomly one observation from each group_id.
If it can be done in subqueries, it's even better.
Thanks. |
c****0
发帖数: 14490 | 2 是指一组数按group_id可以分为几个小组，然后你要在每个小组中randomly选一个obs
吗？
如果是，
说下想法，顺便等高手指正
1.用stata
sample 1，by group_id
2.用sas
PROC SURVEYSELECT DATA=temp；
STRATA variables; *这里的STRATA 变量要先sort过
3.如果取一些数，也可以考虑create new random variable，一般我用 random=ranuni
(n);然后sort random或者设条件取sample
【在 s*********h 的大作中提到】
: I want to select randomly one observation from each group_id.
: If it can be done in subqueries, it's even better.
: Thanks.
|
s*********h
发帖数: 6288 | 3 多谢回帖。
但是我想在teradata里面完成，不借用其他统计软件。
obs
ranuni
【在 c****0 的大作中提到】
: 是指一组数按group_id可以分为几个小组，然后你要在每个小组中randomly选一个obs
: 吗？
: 如果是，
: 说下想法，顺便等高手指正
: 1.用stata
: sample 1，by group_id
: 2.用sas
: PROC SURVEYSELECT DATA=temp；
: STRATA variables; *这里的STRATA 变量要先sort过
: 3.如果取一些数，也可以考虑create new random variable，一般我用 random=ranuni
|
b*********n
发帖数: 2975 | 4 use sample 1 after your code
or generate random number function and order it and top 1 like SAS did
I want to select randomly one observation from each group_id.
If it can be done in subqueries, it's even better.
Thanks.
【在 s*********h 的大作中提到】
: I want to select randomly one observation from each group_id.
: If it can be done in subqueries, it's even better.
: Thanks.
|
c****0
发帖数: 14490 | 5 哦，没看清teredata，咳咳~那个木有用过，╮(╯﹏╰）╭
加油！
【在 s*********h 的大作中提到】
: 多谢回帖。
: 但是我想在teradata里面完成，不借用其他统计软件。
:
: obs
: ranuni
|
s*********h
发帖数: 6288 | 6 this is a good way. Thanks.
BTW, is it efficient? I was hoping there is a generic way of doing it.
【在 b*********n 的大作中提到】
: use sample 1 after your code
: or generate random number function and order it and top 1 like SAS did
:
: I want to select randomly one observation from each group_id.
: If it can be done in subqueries, it's even better.
: Thanks.
|
b*********n
发帖数: 2975 | 7 sample 1 is from teradata itself, should very efficient,
however, if you want to have a very good random generator, you may try some
numerical libary by Fortran/C++ and then
insert the generated random value into your table, then top 1
it also not a big deal for teradata
this is a good way. Thanks.
BTW, is it efficient? I was hoping there is a generic way of doing it.
【在 s*********h 的大作中提到】
: this is a good way. Thanks.
: BTW, is it efficient? I was hoping there is a generic way of doing it.
|
