Ran |
Ran013: congruential combined.
Returns integer random numbers uniformly distributed within [0,4294967295]
(that means [0,2^32-1]. The period is about 2^125 > 4.25*10^37.
Inheritance HierarchyNamespace: Altaxo.Calc.Probability.Old
Assembly: AltaxoCore (in AltaxoCore.dll) Version: 4.8.3572.0 (4.8.3572.0)
SyntaxC#
public class Ran013 : RandomGenerator
The Ran013 type exposes the following members.
Constructors| Name | Description | |
|---|---|---|
 | Ran013 | Initializes a new instance of the Ran013 class. |
| Ran013(UInt32) | Initializes a new instance of the Ran013 class with a specified seed. |
Properties| Name | Description | |
|---|---|---|
 | Maximum | The maximum value of the random number which can be returned. (Inherited from RandomGenerator) |
| Seed | Gets the current seed value. (Inherited from RandomGenerator) |
Methods| Name | Description | |
|---|---|---|
| Equals | Determines whether the specified object is equal to the current object. (Inherited from Object) |
 | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object) |
| GetHashCode | Serves as the default hash function. (Inherited from Object) |
| GetType | Gets the Type of the current instance. (Inherited from Object) |
| Long | The generation function. (Overrides RandomGeneratorLong) |
| MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object) |
| ToString | Returns a string that represents the current object. (Inherited from Object) |
Fields| Name | Description | |
|---|---|---|
 | max_val | Uniform long int values within [0...max_val]. (Inherited from RandomGenerator) |
| seed | The seed of the random generator. (Inherited from RandomGenerator) |
Remarks
- At least 32 bit long int is required, but works with any larger
word lengths
- Reference:
This is algorithm "mzran13" from
G. Marsaglia and A. Zaman,
"Some portable very-long-period random number generators",
Computers in Physics, Vol. 8, No. 1, Jan/Feb 1994.
In the original implementation the algorithm relies on 32-bit
arithmetics with implicit modulo 2^32 on overflow. Since the
the size of unsigned longs may not always be 32 bit the
modulo 2^32 is coded explicitly using masks.
The performance loss is not very important.
The original code reads:
long s;
if (y > x+c) {
s = y - (x+c); c = 0;
} else {
s = y - (x+c) - 18; c = 1;
}
x = y;
y = z;
return ((z = s) + (n - 69069 * n + 1013904243));
^
Here it contains a misprint
Should really be a "=" !
See Also