"Standard" lists of "random" numbers

[mrblister]

Hello,

I have an excel sheet which I want to run tests on large sets of input numbers. The number sets are processed with some random inputs involved, and the outputs of the system are saved. Ideally, the best way to test the number sets is to repeatedly test the same input set many times (with new randomized each time) and then run averages on the outputs, before testing the next number set. But I only want to run a few tests on each input set. So I would like to "standardize" my list of random numbers so that I can get more consistent results with less tests.

Is there a way to generate a static random list of values? I'm looking for something more ordered/standardized than using a RAND() function or similar and then copying the static values. For example:

1. Back when I was younger, one of the programming languages I used had a random number generating function (I don't remember the language), but you needed to specify a seed value or else if would generate the same numbers each time. Is there a way to get Excel to generate an unseeded list of "random" values?
2. Is there a list somewhere of "standard" "random" unseeded values I could use?
3. Alternatively I could create my own "randomize" function, using a long string as a seed, and for example, running some sort of hash formula on it?

Other ideas are welcome. Note I would prefer to not use VBA... at that point I would rather just go with the fallback plan of generating lists of random numbers, and then "freezing" those values.

Thanks in advance!

 

[saboh12617]

Hello,

As far as I know, there is no way to seed the random functions in Excel. In VBA however, you can use the Randomize statement (VBA) | Microsoft Learn to reset the seed.

If you need to create "more random" numbers than the ones provided by the default functions, you should use an Add-in, or why not a website like this one RANDOM.ORG - Sequence Generator. It's good, fast and allows parameters.

 

[jimrward]

It’s always been an issue with random numbers in programming languages
Randomise goes some way to help but using the same seed gives you similar results
One method is to use seconds or milliseconds from the system clock as the seed in the randomise statement the sequence wil repeat but no as predicted

 

[mrblister]

Hello! Thanks for the responses, but to clarify, my request is a bit of an odd one... instead of asking for more-random numbers, I guess I am technically asking for less-random. For example, a list of "standard" random numbers.

 

[Skyybot]

To help me wrap my brain around this; Would you be able to provide an example of "random standard" numbers?

 

[StephenCrump]

There are two parts to your question:

Is there a way to generate a static random list of values?

Yes, use Excel's RAND() function to generate a sufficiently large number of results, and copy/paste the values, as you suggested.

I'm looking for something more ordered/standardized

I only want to run a few tests on each input set. So I would like to "standardize" my list of random numbers so that I can get more consistent results with less tests.

If you're modelling a stochastic process, you'll need to run a sufficiently large number of tests to fully capture the distribution of results, including any tail(s). You may be able to run fewer tests, and get similar results, but in general, the fewer the tests the more variable will be the results.

A static list of random numbers has some advantages, e.g. provided the list is sufficiently large it'll test the scenarios just as well as generating new random numbers, will save computation time, and will allow you to exactly replicate results for different scenarios on repeat runs.

But it doesn't make any sense to talk about standardising your random numbers to achieve the same results from fewer tests.