topic Re: How can I print random number observations in Data set? in SAS Programming

How can I print random number observations in Data set?

Riteshdell — Wed, 22 Feb 2017 18:49:03 GMT

Hello Techiez,

I am looking for some solution where I can print some selected random number of observation of data set.

suppose a Data set contains 100 observation and i want to print some random observation like 8,25,47,56 observation.

How can we do it.

Can any one help me on it.

thanks in advance.

Regards,

Ritesh

Re: How can I print random number observations in Data set?

art297 — Wed, 22 Feb 2017 18:58:03 GMT

You can always select then print them. e.g.:

data temp;
  set sashelp.class;
  if _n_ in (5,8,15);
run;

proc print;
run;

Art, CEO, AnalystFinder.com

Re: How can I print random number observations in Data set?

Riteshdell — Wed, 22 Feb 2017 19:10:05 GMT

Thanks Art297, I understood your solution and it helped me to understand it.

but If I want to print without creating any other dataset, I mean in existing dataset.

Is there any print option is available.

Many thanks for your solution.

Re: How can I print random number observations in Data set?

art297 — Wed, 22 Feb 2017 19:17:21 GMT

If your file contains observation numbers you could use the where option when specifying your dataset.

Art, CEO, AnalystFinder.com

Re: How can I print random number observations in Data set?

mkeintz — Wed, 22 Feb 2017 19:21:15 GMT

I didn't know this couild work (becuase the where statement has no reference to any data set variables), but your question made me test it. And it does work:

proc print data=sashelp.class;

where ranuni(267892343)<=.5;

run;

PS: It's random but not a predetermined subset

Re: How can I print random number observations in Data set?

Shmuel — Wed, 22 Feb 2017 19:20:21 GMT

If you know ahead what observations yo want to print, you may try next code:

proc print data=<dataset_name> (where=(_N_ in (5,25,40,18));

var ... ;

run;

Re: How can I print random number observations in Data set?

nehalsanghvi — Wed, 22 Feb 2017 19:23:34 GMT

If you have SAS/STAT, this is another option:

proc surveyselect data=yourdata method=srs n=5 out=sample;
run;

proc print data=Sample;
run;

If you are using only Base SAS, this is another way, change the seed in the ranuni function to get a different sort order each time:

proc sql;
create table randomorder as
select *
from yourdata
order by ranuni(5678);
quit;

proc print data=randomorder (obs=3);
run;

Re: How can I print random number observations in Data set?

Riteshdell — Wed, 22 Feb 2017 19:23:26 GMT

I didn't understand your Where Line statement, Can you Please describe it .

Re: How can I print random number observations in Data set?

art297 — Wed, 22 Feb 2017 19:27:12 GMT

@Shmuel: I don't believe _n_ is available outside of a datastep.

Art, CEO, AnalystFinder.com

Re: How can I print random number observations in Data set?

mkeintz — Wed, 22 Feb 2017 22:02:19 GMT

The WHERE statement is a filter to tell SAS to keep only those observations that qualify.

So I could have said

where sex='F';

to get only the females,

or even use a function in the where statement:

where sqrt(height/age)>.75;

to get tall students.

Instead I used another function: RANUNI (generates a uniformly random variate between 0 and 1). By constraining it to be less than 0.5 I will get approximately half the cases.

Edit addtion: not just "half the cases" but a quasi-random half.

Another edit addition: Using the IFN function, you can even do differing sampling fractions based on the value of data variables:

proc print data=sashelp.class;

where ranuni(10598150)< ifn(sex='M',.8,.3);

run;

differing samplings

Re: How can I print random number observations in Data set?

mkeintz — Wed, 22 Feb 2017 19:36:37 GMT

And even in a data step, it can't be used in a where statement.