QGIS API Documentation  2.14.0-Essen
Public Types | Public Member Functions | Static Public Member Functions | List of all members
QgsStatisticalSummary Class Reference

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

#include <qgsstatisticalsummary.h>

Public Types

enum  Statistic {
  Count = 1, 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 | 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 calculate (const QList< double > &values)
 Calculates summary statistics for a list of values. More...
 
int count () const
 Returns calculated count of values. 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 39 of file qgsstatisticalsummary.h.

Member Enumeration Documentation

Enumeration of flags that specify statistics to be calculated.

Enumerator
Count 

Count.

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 44 of file qgsstatisticalsummary.h.

Constructor & Destructor Documentation

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

Constructor for QgsStatisticalSummary.

Parameters
statsflags for statistics to calculate

Definition at line 28 of file qgsstatisticalsummary.cpp.

QgsStatisticalSummary::~QgsStatisticalSummary ( )
virtual

Definition at line 34 of file qgsstatisticalsummary.cpp.

Member Function Documentation

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

Calculates summary statistics for a list of values.

Parameters
valueslist of doubles

Definition at line 62 of file qgsstatisticalsummary.cpp.

int QgsStatisticalSummary::count ( ) const
inline

Returns calculated count of values.

Definition at line 102 of file qgsstatisticalsummary.h.

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

Returns the friendly display name for a statistic.

Parameters
statisticstatistic to return name for

Definition at line 237 of file qgsstatisticalsummary.cpp.

double QgsStatisticalSummary::firstQuartile ( ) const
inline

Returns the first quartile of the values.

The quartile is calculated using the "Tukey's hinges" method.

See also
thirdQuartile
interQuartileRange

Definition at line 166 of file qgsstatisticalsummary.h.

double QgsStatisticalSummary::interQuartileRange ( ) const
inline

Returns the inter quartile range of the values.

The quartiles are calculated using the "Tukey's hinges" method.

See also
firstQuartile
thirdQuartile

Definition at line 180 of file qgsstatisticalsummary.h.

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.

See also
minority

Definition at line 159 of file qgsstatisticalsummary.h.

double QgsStatisticalSummary::max ( ) const
inline

Returns calculated maximum from values.

Definition at line 123 of file qgsstatisticalsummary.h.

double QgsStatisticalSummary::mean ( ) const
inline

Returns calculated mean of values.

Definition at line 110 of file qgsstatisticalsummary.h.

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.

Definition at line 115 of file qgsstatisticalsummary.h.

double QgsStatisticalSummary::min ( ) const
inline

Returns calculated minimum from values.

Definition at line 119 of file qgsstatisticalsummary.h.

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.

See also
majority

Definition at line 152 of file qgsstatisticalsummary.h.

double QgsStatisticalSummary::range ( ) const
inline

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

Definition at line 127 of file qgsstatisticalsummary.h.

void QgsStatisticalSummary::reset ( )

Resets the calculated values.

Definition at line 39 of file qgsstatisticalsummary.cpp.

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.

See also
stDev

Definition at line 139 of file qgsstatisticalsummary.h.

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
statsflags for statistics to calculate
See also
statistics

Definition at line 83 of file qgsstatisticalsummary.h.

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

Returns the value of a specified statistic.

Parameters
statstatistic to return
Returns
calculated value of statistic

Definition at line 197 of file qgsstatisticalsummary.cpp.

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 76 of file qgsstatisticalsummary.h.

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.

See also
sampleStDev

Definition at line 133 of file qgsstatisticalsummary.h.

double QgsStatisticalSummary::sum ( ) const
inline

Returns calculated sum of values.

Definition at line 106 of file qgsstatisticalsummary.h.

double QgsStatisticalSummary::thirdQuartile ( ) const
inline

Returns the third quartile of the values.

The quartile is calculated using the "Tukey's hinges" method.

See also
firstQuartile
interQuartileRange

Definition at line 173 of file qgsstatisticalsummary.h.

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 145 of file qgsstatisticalsummary.h.


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