BasicStatistics< RealT > Class Template Reference

Calculates some basic statistical parameters of a distribution: sum, mean, variance, and provides the normal approximation. More...

#include <OpenMS/MATH/STATISTICS/BasicStatistics.h>

Inheritance diagram for BasicStatistics< RealT >:

Public Types
typedef RealT	RealType
	The real type specified as template argument. More...
typedef std::vector< RealType >	probability_container
typedef std::vector< RealType >	coordinate_container

Public Member Functions
	BasicStatistics ()
	Default constructor. More...
	BasicStatistics (BasicStatistics const &arg)
	Copy constructor. More...
BasicStatistics &	operator= (BasicStatistics const &arg)
	Assignment. More...
void	clear ()
	Set sum, mean, and variance to zero. More...
template<typename ProbabilityIterator >
void	update (ProbabilityIterator probability_begin, ProbabilityIterator const probability_end)
	This does the actual calculation. More...
template<typename ProbabilityIterator , typename CoordinateIterator >
void	update (ProbabilityIterator const probability_begin, ProbabilityIterator const probability_end, CoordinateIterator const coordinate_begin)
	This does the actual calculation. More...
RealType	mean () const
	Returns the mean. More...
void	setMean (RealType const &mean)
RealType	variance () const
	Returns the variance. More...
void	setVariance (RealType const &variance)
RealType	sum () const
	Returns the sum. More...
void	setSum (RealType const &sum)
RealType	normalDensity_sqrt2pi (RealType coordinate) const
	Returns the density of the normal approximation at point, multiplied by sqrt( 2 * pi ). This saves a division operation compared to normalDensity() More...
RealType	normalDensity (RealType const coordinate) const
	See normalDensity_sqrt2pi(). Returns the density of the normal distribution at point. More...
void	normalApproximation (probability_container &probability)
	The argument probability is filled with values according to the normal approximation. Its size() is not changed. The approximation takes place at coordinate positions 0, 1, ..., size()-1. More...
void	normalApproximation (probability_container &probability, typename probability_container::size_type const size)
void	normalApproximation (probability_container &probability, coordinate_container const &coordinate)
	The argument probability is filled with values according to the normal approximation. The second argument coordinate contains the positions where the approximation takes place. probability.size() is set to coordinate.size(). More...

Static Public Member Functions
static RealType	sqrt2pi ()
	Returns sqrt( 2 * pi ), which is useful to normalize the result of normalDensity_sqrt2pi(). More...

Protected Attributes
Protected Members
RealType	mean_
RealType	variance_
RealType	sum_

Private Member Functions
Private Methods
void	normalApproximationHelper_ (probability_container &probability, typename probability_container::size_type const size)
void	normalApproximationHelper_ (probability_container &probability, coordinate_container const &coordinate)

Related Functions
(Note that these are not member functions.)
std::ostream &	operator<< (std::ostream &os, BasicStatistics &arg)
	A convenient overload for debugging purposes. More...

Detailed Description

template<typename RealT = double>
class OpenMS::Math::BasicStatistics< RealT >

Calculates some basic statistical parameters of a distribution: sum, mean, variance, and provides the normal approximation.

The intended usage is as follows:

• create an instance
• set the basic statistical parameters by either
  • calling one of the update() member functions, or
  • using the set... methods
• do something with the basic statistical parameters, e.g.
  • using the get... methods, or
  • obtain samples from a normal approximation with these parameters
  • whatever member function you might want to add to this class ;-)

Member Typedef Documentation

coordinate_container

typedef std::vector<RealType> coordinate_container

probability_container

typedef std::vector<RealType> probability_container

RealType

typedef RealT RealType

The real type specified as template argument.

Constructor & Destructor Documentation

BasicStatistics() [1/2]

BasicStatistics ( )

inline

Default constructor.

BasicStatistics() [2/2]

BasicStatistics ( BasicStatistics< RealT > const &  arg )

inline

Copy constructor.

Member Function Documentation

clear()

void clear ( )

inline

Set sum, mean, and variance to zero.

mean()

RealType mean ( ) const

inline

Returns the mean.

normalApproximation() [1/3]

void normalApproximation ( probability_container &  probability )

inline

The argument probability is filled with values according to the normal approximation. Its size() is not changed. The approximation takes place at coordinate positions 0, 1, ..., size()-1.

normalApproximation() [2/3]

void normalApproximation ( probability_container &  probability, coordinate_container const &  coordinate  )

inline

The argument probability is filled with values according to the normal approximation. The second argument coordinate contains the positions where the approximation takes place. probability.size() is set to coordinate.size().

normalApproximation() [3/3]

void normalApproximation ( probability_container &  probability, typename probability_container::size_type const  size  )

inline

The argument probability is filled with values according to the normal approximation. Its size() is set to size. The approximation takes place at coordinate positions 0, 1, ..., size-1.

normalApproximationHelper_() [1/2]

void normalApproximationHelper_ ( probability_container &  probability, coordinate_container const &  coordinate  )

inlineprivate

normalApproximationHelper_() [2/2]

void normalApproximationHelper_ ( probability_container &  probability, typename probability_container::size_type const  size  )

inlineprivate

normalDensity()

RealType normalDensity ( RealType const  coordinate ) const

inline

See normalDensity_sqrt2pi(). Returns the density of the normal distribution at point.

normalDensity_sqrt2pi()

RealType normalDensity_sqrt2pi ( RealType  coordinate ) const

inline

Returns the density of the normal approximation at point, multiplied by sqrt( 2 * pi ). This saves a division operation compared to normalDensity()

operator=()

BasicStatistics& operator= ( BasicStatistics< RealT > const &  arg )

inline

Assignment.

setMean()

void setMean ( RealType const &  mean )

inline

setSum()

void setSum ( RealType const &  sum )

inline

setVariance()

void setVariance ( RealType const &  variance )

inline

sqrt2pi()

static RealType sqrt2pi ( )

inlinestatic

Returns sqrt( 2 * pi ), which is useful to normalize the result of normalDensity_sqrt2pi().

sum()

RealType sum ( ) const

inline

Returns the sum.

update() [1/2]

void update ( ProbabilityIterator const  probability_begin, ProbabilityIterator const  probability_end, CoordinateIterator const  coordinate_begin  )

inline

This does the actual calculation.

You can call this as often as you like, using different input vectors.

update() [2/2]

void update ( ProbabilityIterator  probability_begin, ProbabilityIterator const  probability_end  )

inline

This does the actual calculation.

You can call this as often as you like, using different input vectors.

Referenced by AsymmetricStatistics< RealT >::update().

variance()

RealType variance ( ) const

inline

Returns the variance.

Friends And Related Function Documentation

operator<<

std::ostream& operator<< ( std::ostream &  os, BasicStatistics< RealT > &  arg  )

friend

A convenient overload for debugging purposes.

Member Data Documentation

mean_

RealType mean_

protected

Referenced by BasicStatistics< CoordinateType >::operator=(), and AsymmetricStatistics< RealT >::update().

sum_

RealType sum_

protected

Referenced by BasicStatistics< CoordinateType >::operator=().

variance_

RealType variance_

protected

Referenced by BasicStatistics< CoordinateType >::operator=(), and AsymmetricStatistics< RealT >::update().