QGIS API Documentation  3.17.0-Master (7a14973234)
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 #include "qgis.h"
24 
25 /***************************************************************************
26  * This class is considered CRITICAL and any change MUST be accompanied with
27  * full unit tests in test_qgsstringstatisticalsummary.py.
28  * See details in QEP #17
29  ****************************************************************************/
30 
44 class CORE_EXPORT QgsStringStatisticalSummary
45 {
46  public:
47 
49  enum Statistic
50  {
51  Count = 1,
52  CountDistinct = 2,
53  CountMissing = 4,
54  Min = 8,
55  Max = 16,
56  MinimumLength = 32,
57  MaximumLength = 64,
58  MeanLength = 128,
59  Minority = 256,
60  Majority = 512,
61  All = Count | CountDistinct | CountMissing | Min | Max | MinimumLength | MaximumLength | MeanLength | Minority | Majority,
62  };
63  Q_DECLARE_FLAGS( Statistics, Statistic )
64 
65 
69  QgsStringStatisticalSummary( QgsStringStatisticalSummary::Statistics stats = QgsStringStatisticalSummary::All );
70 
76  Statistics statistics() const { return mStatistics; }
77 
84  void setStatistics( QgsStringStatisticalSummary::Statistics stats ) { mStatistics = stats; }
85 
89  void reset();
90 
97  void calculate( const QStringList &values );
98 
106  void calculateFromVariants( const QVariantList &values );
107 
122  void addString( const QString &string );
123 
137  void addValue( const QVariant &value );
138 
144  void finalize();
145 
151  QVariant statistic( QgsStringStatisticalSummary::Statistic stat ) const;
152 
156  int count() const { return mCount; }
157 
162  int countDistinct() const { return mValues.keys().count(); }
163 
168  QSet< QString > distinctValues() const { return qgis::listToSet( mValues.keys() ); }
169 
173  int countMissing() const { return mCountMissing; }
174 
178  QString min() const { return mMin; }
179 
183  QString max() const { return mMax; }
184 
188  int minLength() const { return mMinLength; }
189 
193  int maxLength() const { return mMaxLength; }
194 
199  double meanLength() const { return mMeanLength; }
200 
209  QString minority() const { return mMinority; }
210 
219  QString majority() const { return mMajority; }
220 
225  static QString displayName( QgsStringStatisticalSummary::Statistic statistic );
226 
227  private:
228 
229  Statistics mStatistics;
230 
231  int mCount;
232  QMap< QString, int > mValues;
233  int mCountMissing;
234  QString mMin;
235  QString mMax;
236  int mMinLength;
237  int mMaxLength;
238  long mSumLengths;
239  double mMeanLength;
240  QString mMinority;
241  QString mMajority;
242 
243  void testString( const QString &string );
244 };
245 
246 Q_DECLARE_OPERATORS_FOR_FLAGS( QgsStringStatisticalSummary::Statistics )
247 
248 #endif // QGSSTRINGSTATISTICALSUMMARY_H
int maxLength() const
Returns the maximum length of strings.
Statistics statistics() const
Returns flags which specify which statistics will be calculated.
QString majority() const
Returns the most common string.
QString minority() const
Returns the least common string.
Statistic
Enumeration of flags that specify statistics to be calculated.
void setStatistics(QgsStringStatisticalSummary::Statistics stats)
Sets flags which specify which statistics will be calculated.
Q_DECLARE_OPERATORS_FOR_FLAGS(QgsField::ConfigurationFlags) CORE_EXPORT QDataStream &operator<<(QDataStream &out
Writes the field to stream out. QGIS version compatibility is not guaranteed.
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.