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pick a random value from a list for a variable, with or without replacement

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Frequent Learner
Posts: 1

pick a random value from a list for a variable, with or without replacement

For the attached sample dataset, I would like to:

 

1) generate a variable "random_value_norepeat" which equals to a randomly selected number from the variable "value" (any number from the "value" can only be selected for one time, or put it another way, sample without replacement), and

 

2) generate another variable "random_value_repeat" which also equals to a randomly selected number from the variable "value", but the number from the "value" can be selected more than once (sample with replacement).

 

Many thanks!

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Trusted Advisor
Posts: 1,934

Re: pick a random value from a list for a variable, with or without replacement

With replacement

http://blogs.sas.com/content/iml/2014/01/29/sample-with-replacement-in-sas.html

 

Without replacement

Google turns up lots of examples

Respected Advisor
Posts: 4,936

Re: pick a random value from a list for a variable, with or without replacement

proc surveyselect does both. method=srs selects without replacement, method=urs does so with replacement.

PG
SAS Super FREQ
Posts: 3,756

Re: pick a random value from a list for a variable, with or without replacement

All the information you need is at 

http://blogs.sas.com/content/iml/2016/02/15/essential-sampling-methods.html

 

I believe you have to generate each variable separately.  It is not clear if you want all 50 observations or a subset. It is also not clear if you need the values in random order or in the original order.  The easiest way is to use the SAMPLE function in SAS/IML, but since you posted to the Base SAS Community, here is a PROC-based solution to get you started:

 

libname temp "C:\Temp";
data Have;
set temp.have;
call streaminit(1);
u = rand("uniform");
run;

/* without replacement (SRS) */
proc sort data=Have out=SRS(rename=(value=random_value_norepeat));
by u;
run;

/* with replacement (URS) */
proc surveyselect noprint data=temp.Have
     method=urs  
     seed=2
     samprate=1
     outhits
     out=URS(rename=(value=vandom_value_repeat));
run;

/* if you want URS in random order, then generate random uniform and sort */
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