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vtkMinimalStandardRandomSequence Class Reference

Park and Miller Sequence of pseudo random numbers. More...

#include <vtkMinimalStandardRandomSequence.h>

Inheritance diagram for vtkMinimalStandardRandomSequence:
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Collaboration diagram for vtkMinimalStandardRandomSequence:
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Public Types

typedef vtkRandomSequence Superclass
- Public Types inherited from vtkRandomSequence
typedef vtkObject Superclass
- Public Types inherited from vtkObject
typedef vtkObjectBase Superclass

Public Member Functions

virtual const char * GetClassName ()
virtual int IsA (const char *type)
void PrintSelf (ostream &os, vtkIndent indent)
void SetSeed (int value)
void SetSeedOnly (int value)
int GetSeed ()
virtual double GetValue ()
virtual void Next ()
virtual double GetRangeValue (double rangeMin, double rangeMax)

Static Public Member Functions

static int IsTypeOf (const char *type)
static
vtkMinimalStandardRandomSequence
SafeDownCast (vtkObject *o)
static
vtkMinimalStandardRandomSequence
New ()

Protected Member Functions

 vtkMinimalStandardRandomSequence ()
virtual ~vtkMinimalStandardRandomSequence ()
- Protected Member Functions inherited from vtkRandomSequence
 vtkRandomSequence ()
virtual ~vtkRandomSequence ()
- Protected Member Functions inherited from vtkObject
 vtkObject ()
virtual ~vtkObject ()
virtual void RegisterInternal (vtkObjectBase *, int check)
virtual void UnRegisterInternal (vtkObjectBase *, int check)
void InternalGrabFocus (vtkCommand *mouseEvents, vtkCommand *keypressEvents=NULL)
void InternalReleaseFocus ()
- Protected Member Functions inherited from vtkObjectBase
 vtkObjectBase ()
virtual ~vtkObjectBase ()
virtual void CollectRevisions (ostream &os)
virtual void ReportReferences (vtkGarbageCollector *)
 vtkObjectBase (const vtkObjectBase &)
void operator= (const vtkObjectBase &)

Protected Attributes

int Seed

Detailed Description

Park and Miller Sequence of pseudo random numbers.

vtkMinimalStandardRandomSequence is a sequence of statistically independent pseudo random numbers uniformly distributed between 0.0 and 1.0.

The sequence is generated by a prime modulus multiplicative linear congruential generator (PMMLCG) or "Lehmer generator" with multiplier 16807 and prime modulus 2^(31)-1. The authors calls it "minimal standard random number generator"

ref: "Random Number Generators: Good Ones are Hard to Find," by Stephen K. Park and Keith W. Miller in Communications of the ACM, 31, 10 (Oct. 1988) pp. 1192-1201. Code is at page 1195, "Integer version 2"

Correctness test is described in first column, page 1195: A seed of 1 at step 1 should give a seed of 1043618065 at step 10001.

Examples:
vtkMinimalStandardRandomSequence (Examples)
Tests:
vtkMinimalStandardRandomSequence (Tests)

Definition at line 45 of file vtkMinimalStandardRandomSequence.h.

Member Typedef Documentation

Definition at line 49 of file vtkMinimalStandardRandomSequence.h.

Constructor & Destructor Documentation

vtkMinimalStandardRandomSequence::vtkMinimalStandardRandomSequence ( )
protected
virtual vtkMinimalStandardRandomSequence::~vtkMinimalStandardRandomSequence ( )
protectedvirtual

Member Function Documentation

virtual const char* vtkMinimalStandardRandomSequence::GetClassName ( )
virtual

Reimplemented from vtkRandomSequence.

static int vtkMinimalStandardRandomSequence::IsTypeOf ( const char *  name)
static

Return 1 if this class type is the same type of (or a subclass of) the named class. Returns 0 otherwise. This method works in combination with vtkTypeMacro found in vtkSetGet.h.

Reimplemented from vtkRandomSequence.

virtual int vtkMinimalStandardRandomSequence::IsA ( const char *  name)
virtual

Return 1 if this class is the same type of (or a subclass of) the named class. Returns 0 otherwise. This method works in combination with vtkTypeMacro found in vtkSetGet.h.

Reimplemented from vtkRandomSequence.

static vtkMinimalStandardRandomSequence* vtkMinimalStandardRandomSequence::SafeDownCast ( vtkObject o)
static

Reimplemented from vtkRandomSequence.

void vtkMinimalStandardRandomSequence::PrintSelf ( ostream &  os,
vtkIndent  indent 
)
virtual

Methods invoked by print to print information about the object including superclasses. Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes.

Reimplemented from vtkRandomSequence.

static vtkMinimalStandardRandomSequence* vtkMinimalStandardRandomSequence::New ( )
static

Create an object with Debug turned off, modified time initialized to zero, and reference counting on.

Reimplemented from vtkObject.

void vtkMinimalStandardRandomSequence::SetSeed ( int  value)

Set the seed of the random sequence. The following pre-condition is stated page 1197, second column: valid_seed: value>=1 && value<=2147483646 2147483646=(2^31)-2 This method does not have this criterium as a pre-condition (ie it will not fail if an incorrect seed value is passed) but the value is silently changed to fit in the valid range [1,2147483646]. 2147483646 is added to a null or negative value. 2147483647 is changed to be 1 (ie 2147483646 is substracted). Implementation note: it also performs 3 calls to Next() to avoid the bad property that the first random number is proportional to the seed value.

void vtkMinimalStandardRandomSequence::SetSeedOnly ( int  value)

Set the seed of the random sequence. There is no extra internal ajustment. Only useful for writing correctness test. The following pre-condition is stated page 1197, second column 2147483646=(2^31)-2 This method does not have this criterium as a pre-condition (ie it will not fail if an incorrect seed value is passed) but the value is silently changed to fit in the valid range [1,2147483646]. 2147483646 is added to a null or negative value. 2147483647 is changed to be 1 (ie 2147483646 is substracted).

int vtkMinimalStandardRandomSequence::GetSeed ( )

Get the seed of the random sequence. Only useful for writing correctness test.

virtual double vtkMinimalStandardRandomSequence::GetValue ( )
virtual

Current value

Postcondition
unit_range: result>=0.0 && result<=1.0

Implements vtkRandomSequence.

virtual void vtkMinimalStandardRandomSequence::Next ( )
virtual

Move to the next number in the random sequence.

Implements vtkRandomSequence.

virtual double vtkMinimalStandardRandomSequence::GetRangeValue ( double  rangeMin,
double  rangeMax 
)
virtual

Convenient method to return a value in a specific range from the range [0,1. There is an initial implementation that can be overridden by a subclass. There is no pre-condition on the range: - it can be in increasing order: rangeMin<rangeMax - it can be empty: rangeMin=rangeMax - it can be in decreasing order: rangeMin>rangeMax

Postcondition
result_in_range: (rangeMin<=rangeMax && result>=rangeMin && result<=rangeMax) || (rangeMax<=rangeMin && result>=rangeMax && result<=rangeMin)

Member Data Documentation

int vtkMinimalStandardRandomSequence::Seed
protected

Definition at line 102 of file vtkMinimalStandardRandomSequence.h.


The documentation for this class was generated from the following file: