topic Re: How do I generate a random number between a specific range? in Splunk Search

How do I generate a random number between a specific range?

sravani27 — Tue, 18 Sep 2018 20:33:54 GMT

Hi, How can I generate a random number between 1 to 20. I random() function doesn't allow to specify a range. please help

Re: How do I generate a random number between a specific range?

richgalloway — Tue, 18 Sep 2018 20:43:44 GMT

Try using the modulo operator. For example, ... | eval rand=(random() % 20) + 1 | ....

Re: How do I generate a random number between a specific range?

worshamn — Wed, 26 Sep 2018 19:50:46 GMT

Building a bit on @richgalloway 's answer I believe this works and allows you to set the high and low range. I added just some extra fluff for testing, your eval line could just look line 4 with high and low replaced with your range:

| makeresults
| eval high = 100
| eval low = 10
| eval rand = round(((random() % high)/(high)) * (high - low) + low)
| eval inRange = if(rand <= high AND rand >= low, "True", "False")

Re: How do I generate a random number between a specific range?

woodcock — Fri, 20 Dec 2019 10:51:19 GMT

@ppablo_splunk , this one should get moderator-answered.

Re: How do I generate a random number between a specific range?

gbhatti — Fri, 27 Aug 2021 13:20:37 GMT

@worshamn Kudos! Building on your solution I slightly simplified the math.

... | eval rand = random() % (high - low + 1) + low ...

Re: How do I generate a random number between a specific range?

PickleRick — Fri, 27 Aug 2021 13:30:16 GMT

One thing - in case of small ranges it might be negligible but if you want a random number from a big range (like between 0 and 1.5*2^30) performing a modulo on random() will not give you uniform distribution.

Re: How do I generate a random number between a specific range?

gbhatti — Fri, 27 Aug 2021 13:40:39 GMT

@PickleRick I was not aware of this. Thanks for pointing it out.