Assigning random numbers in a particular range 1-18

[chrissowden]

I am trying to assign random numbers 1-18 as a new variable to my dataset.

[Patrick]

The random functions create a value between 0 and 1. If you want values between 1 - 18 then just multiply the value by 18 and then use the ceil() function to shift the result to the next higher integer. Below a code sample using ranuni().

data test;
  do i=1 to 100;
    ran_num=ceil(ranuni(1)*18);
    output;
  end;
  stop;
run;

[Reeza · Accepted solution]

Later versions of SAS support INTEGER as a RAND() option.

X = rand(‘integer’, 1, 18);

If your version doesn’t support this (check under the RAND() function), you can use a modification using the RANUNI() function.

[novinosrin]

Never knew the integer option in rand function. Didn't see it in doc either. Nice. Does it pick on a uniform distribution?

[FreelanceReinh]

The "Integer" distribution has been introduced in SAS 9.4M5 (according to the last comment in https://blogs.sas.com/content/iml/2015/10/05/random-integers-sas.html). Yes, it creates random values "from the discrete uniform distribution on a finite set of integers." (documentation)

For arbitrary random numbers in a range [a,b] there are new optional arguments a, b in RAND('UNIFORM',a,b). They were available, but not yet documented in release 9.4M2.

[novinosrin]

Merci !