QGIS API Documentation  3.9.0-Master (d9ef585e47)
qgsstringstatisticalsummary.h
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1 /***************************************************************************
2  qgsstringstatisticalsummary.h
3  -----------------------------
4  Date : May 2016
5  Copyright : (C) 2016 by Nyall Dawson
6  Email : nyall dot dawson at gmail dot com
7  ***************************************************************************
8  * *
9  * This program is free software; you can redistribute it and/or modify *
10  * it under the terms of the GNU General Public License as published by *
11  * the Free Software Foundation; either version 2 of the License, or *
12  * (at your option) any later version. *
13  * *
14  ***************************************************************************/
15 
16 #ifndef QGSSTRINGSTATISTICALSUMMARY_H
17 #define QGSSTRINGSTATISTICALSUMMARY_H
18 
19 #include <QSet>
20 #include <QVariantList>
21 
22 #include "qgis_core.h"
23 
24 /***************************************************************************
25  * This class is considered CRITICAL and any change MUST be accompanied with
26  * full unit tests in test_qgsstringstatisticalsummary.py.
27  * See details in QEP #17
28  ****************************************************************************/
29 
43 class CORE_EXPORT QgsStringStatisticalSummary
44 {
45  public:
46 
48  enum Statistic
49  {
50  Count = 1,
51  CountDistinct = 2,
52  CountMissing = 4,
53  Min = 8,
54  Max = 16,
55  MinimumLength = 32,
56  MaximumLength = 64,
57  MeanLength = 128,
58  All = Count | CountDistinct | CountMissing | Min | Max | MinimumLength | MaximumLength | MeanLength,
59  };
60  Q_DECLARE_FLAGS( Statistics, Statistic )
61 
62 
66  QgsStringStatisticalSummary( QgsStringStatisticalSummary::Statistics stats = QgsStringStatisticalSummary::All );
67 
73  Statistics statistics() const { return mStatistics; }
74 
81  void setStatistics( QgsStringStatisticalSummary::Statistics stats ) { mStatistics = stats; }
82 
86  void reset();
87 
94  void calculate( const QStringList &values );
95 
103  void calculateFromVariants( const QVariantList &values );
104 
119  void addString( const QString &string );
120 
134  void addValue( const QVariant &value );
135 
141  void finalize();
142 
148  QVariant statistic( QgsStringStatisticalSummary::Statistic stat ) const;
149 
153  int count() const { return mCount; }
154 
159  int countDistinct() const { return mValues.count(); }
160 
165  QSet< QString > distinctValues() const { return mValues; }
166 
170  int countMissing() const { return mCountMissing; }
171 
175  QString min() const { return mMin; }
176 
180  QString max() const { return mMax; }
181 
185  int minLength() const { return mMinLength; }
186 
190  int maxLength() const { return mMaxLength; }
191 
196  double meanLength() const { return mMeanLength; }
197 
202  static QString displayName( QgsStringStatisticalSummary::Statistic statistic );
203 
204  private:
205 
206  Statistics mStatistics;
207 
208  int mCount;
209  QSet< QString > mValues;
210  int mCountMissing;
211  QString mMin;
212  QString mMax;
213  int mMinLength;
214  int mMaxLength;
215  long mSumLengths;
216  double mMeanLength;
217 
218  void testString( const QString &string );
219 };
220 
221 Q_DECLARE_OPERATORS_FOR_FLAGS( QgsStringStatisticalSummary::Statistics )
222 
223 #endif // QGSSTRINGSTATISTICALSUMMARY_H
int maxLength() const
Returns the maximum length of strings.
Statistics statistics() const
Returns flags which specify which statistics will be calculated.
Statistic
Enumeration of flags that specify statistics to be calculated.
void setStatistics(QgsStringStatisticalSummary::Statistics stats)
Sets flags which specify which statistics will be calculated.
int countMissing() const
Returns the number of missing (null) string values.
QString min() const
Returns the minimum (non-null) string value.
int count() const
Returns the calculated count of values.
int minLength() const
Returns the minimum length of strings.
QSet< QString > distinctValues() const
Returns the set of distinct string values.
double meanLength() const
Returns the mean length of strings.
int countDistinct() const
Returns the number of distinct string values.
Calculator for summary statistics and aggregates for a list of strings.
QString max() const
Returns the maximum (non-null) string value.