rand¶
rand berechnet gleichverteilte Zufallszahlen.
-
rmRand = rand() -
rmRand = rand(ssGenerator) -
rmRand = rand(nRows, nColumns) -
rmRand = rand(nRows, nColumns, ssGenerator) -
rmRand = rand(rvSize) -
rmRand = rand(rvSize, ssGenerator)
Returnwert
rmRand ist eine reelle Matrix.
Parameter
-
nRows nr ist die Anzahl an Zeilen.
-
nColumns nc ist die Anzahl an Spalten.
-
rvSize rvSize ist ein Vektor mit zwei Elementen. rvSize[1] ist die Anzahl an Zeilen, rvSize[2] ist die Anzahl an Spalten.
-
ssGenerator Ist einer der folgenden Strings ([a,b] := a <= x <= b, (a,b) := a < x < b):
„mt“ Verwendet den Mersenne-Twister Generator (default). „mt“ ist das gleiche wie „mt:real1“. „mt:real1“ generates a random number on [0,1]-real-interval. „mt:real2“ generates a random number on [0,1)-real-interval. „mt:real3“ generates a random number on (0,1)-real-interval. „mt:int31“ generates a random number on [0,0x7fffffff]-interval. „mt:int32“ generates a random number on [0,0xffffffff]-interval. „mt:res53“ generates a random number on [0,1) with 53-bit resolution. „ranlib“ generates a random number on (0,1)-real-interval.
Beispiel
* srand("test")
1.0000
* rand(3, 3)
* 0.5536 0.7214 0.6267
0.0735 0.9892 0.8892
0.4024 0.0891 0.5894
Mit der folgenden Funktion nach der Box-Muller-Methode können normalverteilte (Gauß-Verteilung) Zufallszahlen erzeugt werden:
def randn(nRows, nColumn)
{
return sqrt( -2.0 * log(1.0 - rand(nRows, nColumn))) .* cos(2 * PI * rand(nRows, nColumn));
}
Die Zahlen von 1 bis 10 in zufälliger Reihenfolge:
sorti(rand(1,10))
6.0000 1.0000 10.0000 7.0000 2.0000 8.0000 9.0000 5.0000 3.0000 4.0000
A C-program for MT19937, with initialization improved 2002/1/26.
Coded by Takuji Nishimura and Makoto Matsumoto.
Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
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3. The names of its contributors may not be used to endorse or promote
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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History
| Version | Beschreibung |
|---|---|
| 5.14.0 | Neuer Parameter ssGenerator |
Siehe auch
id-1224554