/usr/share/gnu-smalltalk/kernel/Random.st is in gnu-smalltalk-common 3.2.5-1build2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 | "======================================================================
|
| Random number Method Definitions
|
|
======================================================================"
"======================================================================
|
| Copyright 1988,92,94,95,99,2000,2001,2002
| Free Software Foundation, Inc.
| Written by Steve Byrne.
|
| This file is part of the GNU Smalltalk class library.
|
| The GNU Smalltalk class library is free software; you can redistribute it
| and/or modify it under the terms of the GNU Lesser General Public License
| as published by the Free Software Foundation; either version 2.1, or (at
| your option) any later version.
|
| The GNU Smalltalk class library is distributed in the hope that it will be
| useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
| General Public License for more details.
|
| You should have received a copy of the GNU Lesser General Public License
| along with the GNU Smalltalk class library; see the file COPYING.LIB.
| If not, write to the Free Software Foundation, 59 Temple Place - Suite
| 330, Boston, MA 02110-1301, USA.
|
======================================================================"
Stream subclass: Random [
| seed |
<category: 'Streams'>
<comment: 'My instances are generator streams that produce random numbers, which are
floating point values between 0 and 1.'>
Random class [
| source |
]
Random class >> seed: aFloat [
"Create a new random number generator whose seed is aFloat"
<category: 'instance creation'>
^(self basicNew)
seed: aFloat;
yourself
]
Random class >> new [
"Create a new random number generator whose seed is given by the
current time on the millisecond clock"
<category: 'instance creation'>
^self basicNew setSeed
]
Random class >> source [
"Return a standard source of random numbers."
<category: 'shortcuts'>
^source isNil ifTrue: [source := self new] ifFalse: [source]
]
Random class >> next [
"Return a random number between 0 and 1 (excluded)"
<category: 'shortcuts'>
^self source next
]
Random class >> between: low and: high [
"Return a random integer between the given extrema"
<category: 'shortcuts'>
^self source between: low and: high
]
chiSquare [
"Compute the chi-square of the random that this class generates."
"the previous algorithm's chi-square was 93.4"
<category: 'testing'>
^self chiSquare: 1000 range: 100
]
chiSquare: n range: r [
"Return the chi-square deduced from calculating n random
numbers in the 0..r range."
<category: 'testing'>
| f t seed |
seed := 0.1234567.
f := Array new: r + 1.
1 to: r + 1 do: [:i | f at: i put: 0].
n timesRepeat:
[seed := (seed + Float pi) squared squared fractionPart.
t := (seed * r) truncated.
f at: t + 1 put: (f at: t + 1) + 1].
t := 0.
1 to: r do: [:i | t := t + (f at: i) squared].
^r asFloat * t / n - n
]
atEnd [
"This stream never ends. Always answer false."
<category: 'basic'>
^false
]
between: low and: high [
"Return a random integer between low and high."
<category: 'basic'>
| i range |
range := high - low + 1.
i := (self next * range) truncated.
^i + low
]
next [
"Return the next random number in the sequence."
"Found on an obscure Japanese manual. Turns out to be good!"
<category: 'basic'>
^seed := (seed + Float pi) squared squared fractionPart
]
nextPut: value [
<category: 'basic'>
self shouldNotImplement
]
seed: aFloat [
"Private - Set the random number seed to aFloat.
Ensure decent results even when integers are passed"
<category: 'private'>
seed := (aFloat / 100000.0 + aFloat) fractionPart.
self next.
self next
]
setSeed [
"Private - Set a random number seed."
<category: 'private'>
seed := Time primSecondClock bitXor: Time millisecondClock.
seed := seed + (Time primNanosecondClock \\ 1000000).
seed := (seed / 4194303.0) fractionPart.
self next.
self next
]
]
|