Calculator for summary statistics for a list of doubles. More...

#include <qgsstatisticalsummary.h>

Public Types
enum	Statistic { Count = 1, CountMissing = 32770, Sum = 2, Mean = 4, Median = 8, StDev = 16, StDevSample = 32, Min = 64, Max = 128, Range = 256, Minority = 512, Majority = 1024, Variety = 2048, FirstQuartile = 4096, ThirdQuartile = 8192, InterQuartileRange = 16384, All = Count \| CountMissing \| Sum \| Mean \| Median \| StDev \| Max \| Min \| Range \| Minority \| Majority \| Variety \| FirstQuartile \| ThirdQuartile \| InterQuartileRange }
	Enumeration of flags that specify statistics to be calculated. More...

Public Member Functions
	QgsStatisticalSummary (const QgsStatisticalSummary::Statistics &stats=All)
	Constructor for QgsStatisticalSummary. More...

virtual	~QgsStatisticalSummary ()

void	addValue (double value)
	Adds a single value to the statistics calculation. More...

void	addVariant (const QVariant &value)
	Adds a single value to the statistics calculation. More...

void	calculate (const QList< double > &values)
	Calculates summary statistics for a list of values. More...

int	count () const
	Returns calculated count of values. More...

int	countMissing () const
	Returns the number of missing (null) values. More...

void	finalize ()
	Must be called after adding all values with addValues() and before retrieving any calculated statistics. More...

double	firstQuartile () const
	Returns the first quartile of the values. More...

double	interQuartileRange () const
	Returns the inter quartile range of the values. More...

double	majority () const
	Returns majority of values. More...

double	max () const
	Returns calculated maximum from values. More...

double	mean () const
	Returns calculated mean of values. More...

double	median () const
	Returns calculated median of values. More...

double	min () const
	Returns calculated minimum from values. More...

double	minority () const
	Returns minority of values. More...

double	range () const
	Returns calculated range (difference between maximum and minimum values). More...

void	reset ()
	Resets the calculated values. More...

double	sampleStDev () const
	Returns sample standard deviation. More...

void	setStatistics (const Statistics &stats)
	Sets flags which specify which statistics will be calculated. More...

double	statistic (Statistic stat) const
	Returns the value of a specified statistic. More...

Statistics	statistics () const
	Returns flags which specify which statistics will be calculated. More...

double	stDev () const
	Returns population standard deviation. More...

double	sum () const
	Returns calculated sum of values. More...

double	thirdQuartile () const
	Returns the third quartile of the values. More...

int	variety () const
	Returns variety of values. More...

Static Public Member Functions
static QString	displayName (Statistic statistic)
	Returns the friendly display name for a statistic. More...

Detailed Description

Calculator for summary statistics for a list of doubles.

Statistics are calculated by calling calculate and passing a list of doubles. The individual statistics can then be retrieved using the associated methods. Note that not all statistics are calculated by default. Statistics which require slower computations are only calculated by specifying the statistic in the constructor or via setStatistics.

Note: Added in version 2.9

Definition at line 41 of file qgsstatisticalsummary.h.

Member Enumeration Documentation

◆ Statistic

enum QgsStatisticalSummary::Statistic

Enumeration of flags that specify statistics to be calculated.

Enumerator
Count	Count.
CountMissing	Number of missing (null) values.
Sum	Sum of values.
Mean	Mean of values.
Median	Median of values.
StDev	Standard deviation of values.
StDevSample	Sample standard deviation of values.
Min	Min of values.
Max	Max of values.
Range	Range of values (max - min)
Minority	Minority of values.
Majority	Majority of values.
Variety	Variety (count of distinct) values.
FirstQuartile	First quartile.
ThirdQuartile	Third quartile.
InterQuartileRange	Inter quartile range (IQR)
All

Definition at line 46 of file qgsstatisticalsummary.h.

Constructor & Destructor Documentation

◆ QgsStatisticalSummary()

QgsStatisticalSummary::QgsStatisticalSummary ( const QgsStatisticalSummary::Statistics & stats = All )

Constructor for QgsStatisticalSummary.

Parameters

stats flags for statistics to calculate

Definition at line 28 of file qgsstatisticalsummary.cpp.

◆ ~QgsStatisticalSummary()

QgsStatisticalSummary::~QgsStatisticalSummary ( )

virtual

Definition at line 34 of file qgsstatisticalsummary.cpp.

Member Function Documentation

◆ addValue()

void QgsStatisticalSummary::addValue ( double value )

Adds a single value to the statistics calculation.

Calling this method allows values to be added to the calculation one at a time. For large quantities of values this may be more efficient then first adding all the values to a list and calling calculate().

Parameters

value value to add

Note: call reset() before adding the first value using this method to clear the results from any previous calculations; finalize() must be called after adding the final value and before retrieving calculated statistics.

See also: calculate(); addVariant(); finalize()

Note: added in QGIS 2.16

Definition at line 76 of file qgsstatisticalsummary.cpp.

◆ addVariant()

void QgsStatisticalSummary::addVariant ( const QVariant & value )

Adds a single value to the statistics calculation.

Calling this method allows values to be added to the calculation one at a time. For large quantities of values this may be more efficient then first adding all the values to a list and calling calculate().

Parameters

value variant containing to add. Non-numeric values are treated as null.

Note: call reset() before adding the first value using this method to clear the results from any previous calculations; finalize() must be called after adding the final value and before retrieving calculated statistics.

See also: addValue(); calculate(); finalize()

Note: added in QGIS 2.16

Definition at line 92 of file qgsstatisticalsummary.cpp.

◆ calculate()

void QgsStatisticalSummary::calculate ( const QList< double > & values )

Calculates summary statistics for a list of values.

Parameters

values list of doubles

Definition at line 64 of file qgsstatisticalsummary.cpp.

◆ count()

int QgsStatisticalSummary::count ( ) const

inline

Returns calculated count of values.

Definition at line 146 of file qgsstatisticalsummary.h.

◆ countMissing()

int QgsStatisticalSummary::countMissing ( ) const

inline

Returns the number of missing (null) values.

Note: added in QGIS 2.16

Definition at line 151 of file qgsstatisticalsummary.h.

◆ displayName()

QString QgsStatisticalSummary::displayName ( QgsStatisticalSummary::Statistic statistic )

static

Returns the friendly display name for a statistic.

Parameters

statistic statistic to return name for

Definition at line 281 of file qgsstatisticalsummary.cpp.

◆ finalize()

void QgsStatisticalSummary::finalize ( )

Must be called after adding all values with addValues() and before retrieving any calculated statistics.

See also: addValue(); addVariant()

Note: added in QGIS 2.16

Definition at line 107 of file qgsstatisticalsummary.cpp.

◆ firstQuartile()

double QgsStatisticalSummary::firstQuartile ( ) const

inline

Returns the first quartile of the values.

The quartile is calculated using the "Tukey's hinges" method. A NaN value may be returned if the first quartile cannot be calculated.

See also: thirdQuartile; interQuartileRange

Definition at line 225 of file qgsstatisticalsummary.h.

◆ interQuartileRange()

double QgsStatisticalSummary::interQuartileRange ( ) const

inline

Returns the inter quartile range of the values.

The quartiles are calculated using the "Tukey's hinges" method. A NaN value may be returned if the IQR cannot be calculated.

See also: firstQuartile; thirdQuartile

Definition at line 241 of file qgsstatisticalsummary.h.

◆ majority()

double QgsStatisticalSummary::majority ( ) const

inline

Returns majority of values.

The majority is the value with most occurances in the list This is only calculated if Statistic::Majority has been specified in the constructor or via setStatistics. A NaN value may be returned if the majority cannot be calculated.

See also: minority

Definition at line 217 of file qgsstatisticalsummary.h.

◆ max()

double QgsStatisticalSummary::max ( ) const

inline

Returns calculated maximum from values.

A NaN value may be returned if the maximum cannot be calculated.

Definition at line 176 of file qgsstatisticalsummary.h.

◆ mean()

double QgsStatisticalSummary::mean ( ) const

inline

Returns calculated mean of values.

A NaN value may be returned if the mean cannot be calculated.

Definition at line 160 of file qgsstatisticalsummary.h.

◆ median()

double QgsStatisticalSummary::median ( ) const

inline

Returns calculated median of values.

This is only calculated if Statistic::Median has been specified in the constructor or via setStatistics. A NaN value may be returned if the median cannot be calculated.

Definition at line 166 of file qgsstatisticalsummary.h.

◆ min()

double QgsStatisticalSummary::min ( ) const

inline

Returns calculated minimum from values.

A NaN value may be returned if the minimum cannot be calculated.

Definition at line 171 of file qgsstatisticalsummary.h.

◆ minority()

double QgsStatisticalSummary::minority ( ) const

inline

Returns minority of values.

The minority is the value with least occurances in the list This is only calculated if Statistic::Minority has been specified in the constructor or via setStatistics. A NaN value may be returned if the minority cannot be calculated.

See also: majority

Definition at line 209 of file qgsstatisticalsummary.h.

◆ range()

double QgsStatisticalSummary::range ( ) const

inline

Returns calculated range (difference between maximum and minimum values).

A NaN value may be returned if the range cannot be calculated.

Definition at line 181 of file qgsstatisticalsummary.h.

◆ reset()

void QgsStatisticalSummary::reset ( )

Resets the calculated values.

Definition at line 39 of file qgsstatisticalsummary.cpp.

◆ sampleStDev()

double QgsStatisticalSummary::sampleStDev ( ) const

inline

Returns sample standard deviation.

This is only calculated if Statistic::StDev has been specified in the constructor or via setStatistics. A NaN value may be returned if the standard deviation cannot be calculated.

See also: stDev

Definition at line 195 of file qgsstatisticalsummary.h.

◆ setStatistics()

void QgsStatisticalSummary::setStatistics ( const Statistics & stats )

inline

Sets flags which specify which statistics will be calculated.

Some statistics are always calculated (eg sum, min and max).

Parameters

stats flags for statistics to calculate

See also: statistics

Definition at line 86 of file qgsstatisticalsummary.h.

◆ statistic()

double QgsStatisticalSummary::statistic ( QgsStatisticalSummary::Statistic stat ) const

Returns the value of a specified statistic.

Parameters

stat	statistic to return

Returns: calculated value of statistic. A NaN value may be returned for invalid statistics.

Definition at line 239 of file qgsstatisticalsummary.cpp.

◆ statistics()

Statistics QgsStatisticalSummary::statistics ( ) const

inline

Returns flags which specify which statistics will be calculated.

Some statistics are always calculated (eg sum, min and max).

See also: setStatistics

Definition at line 79 of file qgsstatisticalsummary.h.

◆ stDev()

double QgsStatisticalSummary::stDev ( ) const

inline

Returns population standard deviation.

This is only calculated if Statistic::StDev has been specified in the constructor or via setStatistics. A NaN value may be returned if the standard deviation cannot be calculated.

See also: sampleStDev

Definition at line 188 of file qgsstatisticalsummary.h.

◆ sum()

double QgsStatisticalSummary::sum ( ) const

inline

Returns calculated sum of values.

Definition at line 155 of file qgsstatisticalsummary.h.

◆ thirdQuartile()

double QgsStatisticalSummary::thirdQuartile ( ) const

inline

Returns the third quartile of the values.

The quartile is calculated using the "Tukey's hinges" method. A NaN value may be returned if the third quartile cannot be calculated.

See also: firstQuartile; interQuartileRange

Definition at line 233 of file qgsstatisticalsummary.h.

◆ variety()

int QgsStatisticalSummary::variety ( ) const

inline

Returns variety of values.

The variety is the count of unique values from the list. This is only calculated if Statistic::Variety has been specified in the constructor or via setStatistics.

Definition at line 201 of file qgsstatisticalsummary.h.

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

/tmp/buildd/qgis-2.18.21+99unstable/src/core/qgsstatisticalsummary.h
/tmp/buildd/qgis-2.18.21+99unstable/src/core/qgsstatisticalsummary.cpp

Public Types

Public Member Functions

Static Public Member Functions

Detailed Description

Member Enumeration Documentation

◆ Statistic

Constructor & Destructor Documentation

◆ QgsStatisticalSummary()

◆ ~QgsStatisticalSummary()

Member Function Documentation

◆ addValue()

◆ addVariant()

◆ calculate()

◆ count()

◆ countMissing()

◆ displayName()

◆ finalize()

◆ firstQuartile()

◆ interQuartileRange()

◆ majority()

◆ max()

◆ mean()

◆ median()

◆ min()

◆ minority()

◆ range()

◆ reset()

◆ sampleStDev()

◆ setStatistics()

◆ statistic()

◆ statistics()

◆ stDev()

◆ sum()

◆ thirdQuartile()

◆ variety()