Class ALFGenerator

Represents a Additive Lagged Fibonacci pseudo-random number generator.

Inheritance

System.Object

Generator

ALFGenerator

Inherited Members

System.Object.ToString()

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

Namespace: Experior.Core.Mathematics.Statistics.Generators.Pseudo

Assembly: Experior.Core.dll

Syntax

public class ALFGenerator : Generator

Remarks

The ALFGenerator type bases upon the implementation in the Boost Random Number Library. It uses the modulus 2³² and by default the "lags" 418 and 1279, which can be adjusted through the associated ShortLag and LongLag properties. Some popular pairs are presented on Wikipedia - Lagged Fibonacci generator.

Constructors

ALFGenerator()

Initializes a new instance of the ALFGenerator class, using a time-dependent default seed value.

Declaration

public ALFGenerator()

ALFGenerator(Int32)

Initializes a new instance of the ALFGenerator class, using the specified seed value.

Declaration

public ALFGenerator(int seed)

Parameters

Type	Name	Description
System.Int32	seed	A number used to calculate a starting value for the pseudo-random number sequence. If a negative number is specified, the absolute value of the number is used.

ALFGenerator(UInt32)

Initializes a new instance of the StandardGenerator class, using the specified seed value.

Declaration

[CLSCompliant(false)]
public ALFGenerator(uint seed)

Parameters

Type	Name	Description
System.UInt32	seed	An unsigned number used to calculate a starting value for the pseudo-random number sequence.

Properties

CanReset

Gets a value indicating whether the ALFGenerator can be reset, so that it produces the same pseudo-random number sequence again.

Declaration

public override bool CanReset { get; }

Property Value

Type	Description
System.Boolean	`true` if this instance can reset; otherwise, `false`.

Overrides

Generator.CanReset

LongLag

Gets or sets the long lag of the Lagged Fibonacci pseudo-random number generator.

Declaration

public int LongLag { get; set; }

Property Value

Type	Description
System.Int32	The long lag.

Remarks

Call IsValidLongLag(Int32) to determine whether a value is valid and therefor assignable.

ShortLag

Gets or sets the short lag of the Lagged Fibonacci pseudo-random number generator.

Declaration

public int ShortLag { get; set; }

Property Value

Type	Description
System.Int32	The short lag.

Remarks

Call IsValidShortLag(Int32) to determine whether a value is valid and therefor assignable.

Methods

IsValidLongLag(Int32)

Determines whether the specified value is valid for parameter LongLag.

Declaration

public bool IsValidLongLag(int value)

Parameters

Type	Name	Description
System.Int32	value	The value to check.

Returns

Type	Description
System.Boolean	true if value is greater than ShortLag; otherwise, false.

IsValidShortLag(Int32)

Determines whether the specified value is valid for parameter ShortLag.

Declaration

public bool IsValidShortLag(int value)

Parameters

Type	Name	Description
System.Int32	value	The value to check.

Returns

Type	Description
System.Boolean	true if value is greater than 0; otherwise, false.

Next()

Returns a nonnegative random number less than System.Int32.MaxValue.

Declaration

public override int Next()

Returns

Type	Description
System.Int32	A 32-bit signed integer greater than or equal to 0, and less than System.Int32.MaxValue; that is, the range of return values includes 0 but not `int.MaxValue.MaxValue`.

Overrides

Generator.Next()

Next(Int32)

Returns a nonnegative random number less than the specified maximum.

Declaration

public override int Next(int maxValue)

Parameters

Type	Name	Description
System.Int32	maxValue	The exclusive upper bound of the random number to be generated. `maxValue` must be greater than or equal to 0.

Returns

Type	Description
System.Int32	A 32-bit signed integer greater than or equal to 0, and less than `maxValue`; that is, the range of return values includes 0 but not `maxValue`.

Overrides

Generator.Next(Int32)

Exceptions

Type	Condition
System.ArgumentOutOfRangeException

Next(Int32, Int32)

Returns a random number within the specified range.

Declaration

public override int Next(int minValue, int maxValue)

Parameters

Type	Name	Description
System.Int32	minValue	The inclusive lower bound of the random number to be generated.
System.Int32	maxValue	The exclusive upper bound of the random number to be generated. `maxValue` must be greater than or equal to `minValue`.

Returns

Type	Description
System.Int32	A 32-bit signed integer greater than or equal to `minValue`, and less than `maxValue`; that is, the range of return values includes `minValue` but not `maxValue`. If `minValue` equals `maxValue`, `minValue` is returned.

Overrides

Generator.Next(Int32, Int32)

Exceptions

Type	Condition
System.ArgumentOutOfRangeException

NextBoolean()

Returns a random Boolean value.

Declaration

public override bool NextBoolean()

Returns

Type	Description
System.Boolean	A System.Boolean value.

Overrides

Generator.NextBoolean()

Remarks

Buffers 31 random bits for future calls, so the random number generator is only invoked once in every 31 calls.

NextBytes(Byte[])

Fills the elements of a specified array of bytes with random numbers.

Declaration

public override void NextBytes(byte[] buffer)

Parameters

Type	Name	Description
System.Byte[]	buffer	An array of bytes to contain random numbers.

Overrides

Generator.NextBytes(Byte[])

Remarks

Each element of the array of bytes is set to a random number greater than or equal to 0, and less than or equal to System.Byte.MaxValue.

Exceptions

Type	Condition
System.ArgumentNullException

NextDouble()

Returns a nonnegative floating point random number less than 1.0.

Declaration

public override double NextDouble()

Returns

Type	Description
System.Double	A double-precision floating point number greater than or equal to 0.0, and less than 1.0; that is, the range of return values includes 0.0 but not 1.0.

Overrides

Generator.NextDouble()

NextDouble(Double)

Returns a nonnegative floating point random number less than the specified maximum.

Declaration

public override double NextDouble(double maxValue)

Parameters

Type	Name	Description
System.Double	maxValue	The exclusive upper bound of the random number to be generated. `maxValue` must be greater than or equal to 0.0.

Returns

Type	Description
System.Double	A double-precision floating point number greater than or equal to 0.0, and less than `maxValue`; that is, the range of return values includes 0 but not `maxValue`.

Overrides

Generator.NextDouble(Double)

Exceptions

Type	Condition
System.ArgumentOutOfRangeException

NextDouble(Double, Double)

Returns a floating point random number within the specified range.

Declaration

public override double NextDouble(double minValue, double maxValue)

Parameters

Type	Name	Description
System.Double	minValue	The inclusive lower bound of the random number to be generated. The range between `minValue` and `maxValue` must be less than or equal to System.Double.MaxValue
System.Double	maxValue	The exclusive upper bound of the random number to be generated. `maxValue` must be greater than or equal to `minValue`. The range between `minValue` and `maxValue` must be less than or equal to System.Double.MaxValue.

Returns

Type	Description
System.Double	A double-precision floating point number greater than or equal to `minValue`, and less than `maxValue`; that is, the range of return values includes `minValue` but not `maxValue`. If `minValue` equals `maxValue`, `minValue` is returned.

Overrides

Generator.NextDouble(Double, Double)

Exceptions

Type	Condition
System.ArgumentOutOfRangeException
System.ArgumentException

NextInclusiveMaxValue()

Returns a nonnegative random number less than or equal to System.Int32.MaxValue.

Declaration

public int NextInclusiveMaxValue()

Returns

Type	Description
System.Int32	A 32-bit signed integer greater than or equal to 0, and less than or equal to System.Int32.MaxValue; that is, the range of return values includes 0 and `int.MaxValue.MaxValue`.

NextUInt()

Returns an unsigned random number.

Declaration

[CLSCompliant(false)]
public uint NextUInt()

Returns

Type	Description
System.UInt32	A 32-bit unsigned integer greater than or equal to System.UInt32.MinValue and less than or equal to .

Reset()

Resets the ALFGenerator, so that it produces the same pseudo-random number sequence again.

Declaration

public override bool Reset()

Returns

Type	Description
System.Boolean	true.

Overrides

Generator.Reset()