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Class: RandomGNUSmalltalk
Object
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+--Stream
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+--Random
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+--RandomGNUSmalltalk
- Package:
- stx:libbasic2
- Category:
- Magnitude-Numbers-Random
- Version:
- rev:
1.2
date: 2018/03/02 16:08:05
- user: cg
- file: RandomGNUSmalltalk.st directory: libbasic2
- module: stx stc-classLibrary: libbasic2
- Author:
- Steve Byrne
- Claus Gittinger
WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
=======================================================================================
DO NOT USE THIS GENERATOR FOR CRYPTOGRAPHY OR OTHER SECURITY RELATED WORK,
because linear congruential generators are predictable and can be broken easily!
Smalltalk/X includes a better generator named RandomGenerator,
which uses the best available generator of the system
(either OS-random, /dev/random or as a less dangerous fallback, an RC4-based random generator).
Please use that one.
=======================================================================================
A simple random numbers - thanks to Steves GNU Smalltalk
This implements a linear congruential maximum period random number generator
which passes the spectral test for randomness for dimensions 2 3 4 5 6.
Notice: although being included here,
this file is NOT covered by the ST/X license, but by
the FSF copyLeft (see copyright method).
You can redistribute it under the terms stated there ...
Also, the price you pay for ST/X does not include a charge for
this file - it has to be considered as a separate piece of
software, which can be copied and given away without any
restriction from my (CG) side.
http://www0.cs.ucl.ac.uk/staff/d.jones/GoodPracticeRNG.pdf
RandomTT800
-
a
new
random
generator
RandomParkMiller
-
another
new
random
generator
accessing-reading
-
maxInteger
-
-
next
-
return the next random number in the range ]0..1[
-
nextBoolean
-
return true or false by random
-
nextInteger
-
return the next integral random number,
in the range 0 .. modulus (which is less than 16r3FFFFFFF).
From Sedgewick's 'Algorithms', based on Lehmer's method.
Take care, this returns an even number after each odd number!
private
-
setSeed: seedValue
-
set the initial seed and intialite the PRNG parameters.
These numbers implement a maximum period generator which passes
the spectral test for randomness for dimensions 2 3 4 5 6 and
the product does not overflow 2 raisedTo:29.
These numbers are carefully choosen, so don't change them,
unless you know what you are doing!
-
step
-
compute the next random integer
|rnd|
rnd := RandomGNUSmalltalk new.
10 timesRepeat:[
Transcript showCR:(rnd next)
]
|
rolling a dice:
|rnd|
rnd := RandomGNUSmalltalk new.
10 timesRepeat:[
Transcript showCR:(rnd nextIntegerBetween:1 and:6)
]
|
|