QGIS API Documentation  3.21.0-Master (56b4176581)
qgsalgorithmkmeansclustering.h
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1 /***************************************************************************
2  qgsalgorithmkmeansclustering.h
3  ---------------------
4  begin : June 2018
5  copyright : (C) 2018 by Nyall Dawson
6  email : nyall dot dawson at gmail dot com
7  ***************************************************************************/
8 
9 /***************************************************************************
10  * *
11  * This program is free software; you can redistribute it and/or modify *
12  * it under the terms of the GNU General Public License as published by *
13  * the Free Software Foundation; either version 2 of the License, or *
14  * (at your option) any later version. *
15  * *
16  ***************************************************************************/
17 
18 #ifndef QGSALGORITHMKMEANSCLUSTERING_H
19 #define QGSALGORITHMKMEANSCLUSTERING_H
20 
21 #define SIP_NO_FILE
22 
23 #include "qgis_sip.h"
24 #include "qgis_analysis.h"
25 #include "qgsprocessingalgorithm.h"
26 
28 
29 
33 class ANALYSIS_EXPORT QgsKMeansClusteringAlgorithm : public QgsProcessingAlgorithm
34 {
35 
36  public:
37 
38  QgsKMeansClusteringAlgorithm() = default;
39  void initAlgorithm( const QVariantMap &configuration = QVariantMap() ) override;
40  QString name() const override;
41  QString displayName() const override;
42  QStringList tags() const override;
43  QString group() const override;
44  QString groupId() const override;
45  QString shortHelpString() const override;
46  QgsKMeansClusteringAlgorithm *createInstance() const override SIP_FACTORY;
47 
48  protected:
49 
50  QVariantMap processAlgorithm( const QVariantMap &parameters,
51  QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
52 
53  private:
54 
55  struct Feature
56  {
57  Feature( QgsPointXY point )
58  : point( point )
59  {}
60 
61  QgsPointXY point;
62  int cluster = -1;
63  };
64 
65  static void initClusters( std::vector< Feature > &points, std::vector< QgsPointXY > &centers, int k, QgsProcessingFeedback *feedback );
66  static void calculateKMeans( std::vector< Feature > &points, std::vector< QgsPointXY > &centers, int k, QgsProcessingFeedback *feedback );
67  static void findNearest( std::vector< Feature > &points, const std::vector< QgsPointXY > &centers, int k, bool &changed );
68  static void updateMeans( const std::vector< Feature > &points, std::vector< QgsPointXY > &centers, std::vector< uint > &weights, int k );
69 
70  friend class TestQgsProcessingAlgs;
71 };
72 
74 
75 #endif // QGSALGORITHMKMEANSCLUSTERING_H
76 
77 
A class to represent a 2D point.
Definition: qgspointxy.h:59
Abstract base class for processing algorithms.
virtual QString group() const
Returns the name of the group this algorithm belongs to.
virtual QString groupId() const
Returns the unique ID of the group this algorithm belongs to.
virtual QString shortHelpString() const
Returns a localised short helper string for the algorithm.
virtual QVariantMap processAlgorithm(const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback) SIP_THROW(QgsProcessingException)=0
Runs the algorithm using the specified parameters.
virtual QString displayName() const =0
Returns the translated algorithm name, which should be used for any user-visible display of the algor...
virtual QgsProcessingAlgorithm * createInstance() const =0
Creates a new instance of the algorithm class.
virtual QStringList tags() const
Returns a list of tags which relate to the algorithm, and are used to assist users in searching for s...
virtual void initAlgorithm(const QVariantMap &configuration=QVariantMap())=0
Initializes the algorithm using the specified configuration.
virtual QString name() const =0
Returns the algorithm name, used for identifying the algorithm.
Contains information about the context in which a processing algorithm is executed.
Base class for providing feedback from a processing algorithm.
#define SIP_FACTORY
Definition: qgis_sip.h:76