Difference between revisions of "Rnd"
(Created page with "<c>rnd</c> Generates a pseudorandom number between 0 and 1 (including 0 but not including 1). === Arguments === {| class="wikitable" |- ! Parameter Name !! Default Value !!...") |
(expanded usage notes and added example) |
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| − | <c>rnd</c> | + | <c>rnd</c> generates a pseudorandom number between 0 and 1 (including 0 but not including 1). |
=== Arguments === | === Arguments === | ||
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{| class="wikitable" | {| class="wikitable" | ||
|- | |- | ||
| − | ! Parameter Name !! | + | ! Parameter Name !! Type !! Meaning |
|- | |- | ||
| ''seed'' || number, optional || if given, reset the sequence with this value. | | ''seed'' || number, optional || if given, reset the sequence with this value. | ||
| Line 15: | Line 15: | ||
of random numbers. If you never specify a seed, then it is | of random numbers. If you never specify a seed, then it is | ||
initialized automatically, generating a unique sequence on each run. | initialized automatically, generating a unique sequence on each run. | ||
| + | |||
| + | Since the result of <c>rnd</c> is between 0 and 1, if you multiply it by some other number ''n'', you get a random value between 0 and ''n''. This is often combined with [[floor]] or [[ceil]] to get a whole number in the range 0 to ''n''-1 or in the range 1 to ''n'', respectively. | ||
| + | |||
| + | |||
| + | == Example == | ||
| + | |||
| + | The following example simulates rolling three ordinary 6-sided dice, generating numbers from 1 to 6 inclusive. `rnd * 6` returns a floating-point number between 0 and 6, and taking [[ceil]] of that rounds it up to a whole number from 1 to 6. | ||
| + | |||
| + | <ms>sum = 0 | ||
| + | for i in range(1, 3) | ||
| + | roll = ceil(rnd * 6) | ||
| + | print "You rolled a " + roll | ||
| + | sum = sum + roll | ||
| + | end for | ||
| + | print "Total: " + sum</ms> | ||
[[Category:Intrinsic Functions]] | [[Category:Intrinsic Functions]] | ||
[[Category:Numeric Functions]] | [[Category:Numeric Functions]] | ||
Latest revision as of 20:15, 15 December 2020
rnd generates a pseudorandom number between 0 and 1 (including 0 but not including 1).
Arguments
| Parameter Name | Type | Meaning |
|---|---|---|
| seed | number, optional | if given, reset the sequence with this value. |
Usage Notes
If given a seed, then the generator is reset with that seed value, allowing you to create repeatable sequences of random numbers. If you never specify a seed, then it is initialized automatically, generating a unique sequence on each run.
Since the result of rnd is between 0 and 1, if you multiply it by some other number n, you get a random value between 0 and n. This is often combined with floor or ceil to get a whole number in the range 0 to n-1 or in the range 1 to n, respectively.
Example
The following example simulates rolling three ordinary 6-sided dice, generating numbers from 1 to 6 inclusive. `rnd * 6` returns a floating-point number between 0 and 6, and taking ceil of that rounds it up to a whole number from 1 to 6.
sum = 0
for i in range(1, 3)
roll = ceil(rnd * 6)
print "You rolled a " + roll
sum = sum + roll
end for
print "Total: " + sum
