Re: is rand random enough to simulate dice rolls?

But I dont wont to do a cryptographically secure application.

I just want to be sure that if I use rand to simulate a six sided die and I repaet the roll 10000 times I will get an average result of 3.5 as expected.

If that's the case, why bother? If the result is other than expected, just output that, a short remark about why this is bad, and let users of specific platforms scratch their own head :P

perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'

Comment on Re: is rand random enough to simulate dice rolls?

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Re^2: is rand random enough to simulate dice rolls? by Discipulus (Canon) on Jan 03, 2021 at 17:03 UTC
thanks shmem and all In effect this sounds the wiser thing to do. I have modified my `.t` file to just emit a warning via diag my $tenk; $tenk += 1 + int( rand(6) ) for 1..10000; my $avg = $tenk/10000; # $avg = 5; # uncomment this line to provoke the warning if ( ($avg < 3.4) or ($avg > 3.6) ){ diag("\n\n\nPROBLEM: you got an average of $avg while was expected + a value > 3.4 and < 3.6\n\n\n". "The average was made on 10000 results.\n". "This can happen in old Perl distribution on some platform +.\n". "In future distributions of this module you might be able +to load a different random number generator\n\n\n\n") } else{ ok ( $avg > 3.4, "average randomness ok (10000d6 / 10000 > 3.4)" ) +; ok ( $avg < 3.6, "average randomness ok (10000d6 / 10000 < 3.6)" ) +; } [download] L* UPDATE nothing critical nor crucial: I'm just started a little project just to clean my rusty hands: it was a long time (for me) without coding :) There are no rules, there are no thumbs.. Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.	[reply] [d/l] [select]
Re^3: is rand random enough to simulate dice rolls? by haukex (Archbishop) on Jan 04, 2021 at 13:20 UTC
Note that you don't really need the two `ok`'s in the `else` since the conditions have already been tested, and in fact they may fail in case `$avg==3.4 or $avg==3.6`. You could just do `else { pass "average randomness ok (3.4 < 10000d6 / 10000 < 3.6)" }` instead.	[reply] [d/l] [select]
Re^4: is rand random enough to simulate dice rolls? by Discipulus (Canon) on Jan 04, 2021 at 13:57 UTC
yes :) I was tempted to put there a `ok ( 1, "average randomness ok..` but seemed stupid. I forgot the `pass` option. Thanks L* There are no rules, there are no thumbs.. Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.	[reply] [d/l] [select]


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