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
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The names of its contributors may not be used to endorse or promote
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"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