Implementation of a logarithmic scale method. More...

#include <qgsclassificationlogarithmic.h>

Inheritance diagram for QgsClassificationLogarithmic:

Public Types
enum	NegativeValueHandling { NoHandling = 0 , Discard , PrependBreak }
	Handling of negative and 0 values in the method. More...

Public Types inherited from QgsClassificationMethod
enum	ClassPosition { LowerBound , Inner , UpperBound }
	Defines the class position. More...

typedef QFlags< MethodProperty >	MethodProperties

enum	MethodProperty { NoFlag = 0 , ValuesNotRequired = 1 << 1 , SymmetricModeAvailable = 1 << 2 , IgnoresClassCount = 1 << 3 }
	Flags for the classification method. More...

Public Member Functions
	QgsClassificationLogarithmic ()

QgsClassificationMethod *	clone () const override
	Returns a clone of the method.

QIcon	icon () const override
	The icon of the method.

QString	id () const override
	The id of the method as saved in the project, must be unique in registry.

QString	labelForRange (double lowerValue, double upperValue, ClassPosition position) const override
	Returns the label for a range.

QString	name () const override
	The readable and translate name of the method.

bool	valuesRequired () const override
	Returns if the method requires values to calculate the classes If not, bounds are sufficient.

Public Member Functions inherited from QgsClassificationMethod
	QgsClassificationMethod (MethodProperties properties=NoFlag, int codeComplexity=1)
	Creates a classification method.

virtual	~QgsClassificationMethod ()

Q_DECL_DEPRECATED QList< QgsClassificationRange >	classes (const QgsVectorLayer *layer, const QString &expression, int nclasses)
	This will calculate the classes for a given layer to define the classes.

QList< QgsClassificationRange >	classes (const QList< double > &values, int nclasses)
	This will calculate the classes for a list of values.

QList< QgsClassificationRange >	classes (double minimum, double maximum, int nclasses)
	This will calculate the classes for defined bounds without any values.

QList< QgsClassificationRange >	classesV2 (const QgsVectorLayer *layer, const QString &expression, int nclasses, QString &error)
	This will calculate the classes for a given layer to define the classes.

int	codeComplexity () const
	Code complexity as the exponent in Big O notation.

QgsClassificationMethod::MethodProperties	flags () const
	Returns the classification flags.

QString	labelFormat () const
	Returns the format of the label for the classes.

QString	labelForRange (const QgsRendererRange &range, ClassPosition position=Inner) const
	Returns the label for a range.

int	labelPrecision () const
	Returns the precision for the formatting of the labels.

bool	labelTrimTrailingZeroes () const
	Returns if the trailing 0 are trimmed in the label.

const QgsProcessingParameterDefinition *	parameterDefinition (const QString &parameterName) const
	Returns the parameter from its name.

QgsProcessingParameterDefinitions	parameterDefinitions () const
	Returns the list of parameters.

QVariantMap	parameterValues () const
	Returns the values of the processing parameters.

virtual void	readXml (const QDomElement &element, const QgsReadWriteContext &context)
	Reads extra information to apply it to the method.

QDomElement	save (QDomDocument &doc, const QgsReadWriteContext &context) const
	Saves the method to a DOM element and return it.

void	setLabelFormat (const QString &format)
	Defines the format of the labels for the classes, using %1 and %2 for the bounds.

void	setLabelPrecision (int labelPrecision)
	Defines the precision for the formatting of the labels.

void	setLabelTrimTrailingZeroes (bool trimTrailingZeroes)
	Defines if the trailing 0 are trimmed in the label.

void	setParameterValues (const QVariantMap &values)
	Defines the values of the additional parameters.

void	setSymmetricMode (bool enabled, double symmetryPoint=0, bool symmetryAstride=false)
	Defines if the symmetric mode is enables and configures its parameters.

bool	symmetricModeAvailable () const
	Returns if the method supports symmetric calculation.

bool	symmetricModeEnabled () const
	Returns if the symmetric mode is enabled.

bool	symmetryAstride () const
	Returns if the symmetric mode is astride if `true`, it will remove the symmetry point break so that the 2 classes form only one.

double	symmetryPoint () const
	Returns the symmetry point for symmetric mode.

virtual void	writeXml (QDomElement &element, const QgsReadWriteContext &context) const
	Writes extra information about the method.

Additional Inherited Members
Static Public Member Functions inherited from QgsClassificationMethod
static QgsClassificationMethod *	create (const QDomElement &element, const QgsReadWriteContext &context)
	Reads the DOM element and return a new classification method from it.

static void	makeBreaksSymmetric (QList< double > &breaks, double symmetryPoint, bool astride)
	Remove the breaks that are above the existing opposite sign classes to keep colors symmetrically balanced around symmetryPoint Does not put a break on the symmetryPoint.

static QList< double >	rangesToBreaks (const QList< QgsClassificationRange > &classes)
	Transforms a list of classes to a list of breaks.

Static Public Attributes inherited from QgsClassificationMethod
static const int	MAX_PRECISION = 15

static const int	MIN_PRECISION = -6

Protected Member Functions inherited from QgsClassificationMethod
void	addParameter (QgsProcessingParameterDefinition *definition)
	Add a parameter to the method.

void	copyBase (QgsClassificationMethod *c) const
	Copy the parameters (shall be used in clone implementation)

QString	formatNumber (double value) const
	Format the number according to label properties.

Detailed Description

Implementation of a logarithmic scale method.

Since: QGIS 3.10

Definition at line 28 of file qgsclassificationlogarithmic.h.

Member Enumeration Documentation

◆ NegativeValueHandling

enum QgsClassificationLogarithmic::NegativeValueHandling

Handling of negative and 0 values in the method.

Since: QGIS 3.12

Enumerator
NoHandling	No handling.
Discard	Negative values are discarded - this will require all values.
PrependBreak	Prepend an extra break to include negative values - this will require all values.

Definition at line 36 of file qgsclassificationlogarithmic.h.

Constructor & Destructor Documentation

◆ QgsClassificationLogarithmic()

QgsClassificationLogarithmic::QgsClassificationLogarithmic ( )

Definition at line 24 of file qgsclassificationlogarithmic.cpp.

Member Function Documentation

◆ clone()

QgsClassificationMethod * QgsClassificationLogarithmic::clone ( ) const

overridevirtual

Returns a clone of the method.

Implementation can take advantage of copyBase method which copies the parameters of the base class

Implements QgsClassificationMethod.

Definition at line 32 of file qgsclassificationlogarithmic.cpp.

◆ icon()

QIcon QgsClassificationLogarithmic::icon ( ) const

overridevirtual

The icon of the method.

Reimplemented from QgsClassificationMethod.

Definition at line 49 of file qgsclassificationlogarithmic.cpp.

◆ id()

QString QgsClassificationLogarithmic::id ( ) const

overridevirtual

The id of the method as saved in the project, must be unique in registry.

Implements QgsClassificationMethod.

Definition at line 44 of file qgsclassificationlogarithmic.cpp.

◆ labelForRange()

QString QgsClassificationLogarithmic::labelForRange	(	double	lowerValue,
		double	upperValue,
		QgsClassificationMethod::ClassPosition	position
	)		const

overridevirtual

Returns the label for a range.

Reimplemented from QgsClassificationMethod.

Definition at line 142 of file qgsclassificationlogarithmic.cpp.

◆ name()

QString QgsClassificationLogarithmic::name ( ) const

overridevirtual

The readable and translate name of the method.

Implements QgsClassificationMethod.

Definition at line 39 of file qgsclassificationlogarithmic.cpp.

◆ valuesRequired()

bool QgsClassificationLogarithmic::valuesRequired ( ) const

overridevirtual

Returns if the method requires values to calculate the classes If not, bounds are sufficient.

Reimplemented from QgsClassificationMethod.

Definition at line 161 of file qgsclassificationlogarithmic.cpp.

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

/build/qgis-3.41.0+git20241214+cea29feecf2+99sid/src/core/classification/qgsclassificationlogarithmic.h
/build/qgis-3.41.0+git20241214+cea29feecf2+99sid/src/core/classification/qgsclassificationlogarithmic.cpp

Public Types

Public Member Functions

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ NegativeValueHandling

Constructor & Destructor Documentation

◆ QgsClassificationLogarithmic()

Member Function Documentation

◆ clone()

◆ icon()

◆ id()

◆ labelForRange()

◆ name()

◆ valuesRequired()