QgsInterpolator Class Reference

Interface class for interpolations. More...

#include <qgsinterpolator.h>

Inheritance diagram for QgsInterpolator:

Classes
struct	LayerData
	A source together with the information about interpolation attribute / z-coordinate interpolation and the type (point, structure line, breakline) More...

Public Types
enum	Result { Success = 0, Canceled, InvalidSource, FeatureGeometryError }
	Result of an interpolation operation. More...
enum	SourceType { SourcePoints, SourceStructureLines, SourceBreakLines }
	Describes the type of input data. More...
enum	ValueSource { ValueAttribute, ValueZ, ValueM }
	Source for interpolated values from features. More...

Public Member Functions
	QgsInterpolator (const QList< QgsInterpolator::LayerData > &layerData)
virtual	~QgsInterpolator ()=default
virtual int	interpolatePoint (double x, double y, double &result, QgsFeedback *feedback=nullptr)=0
	Calculates interpolation value for map coordinates x, y. More...
QList< LayerData >	layerData () const

Protected Member Functions
Result	cacheBaseData (QgsFeedback *feedback=nullptr)
	Caches the vertex and value data from the provider. More...

Protected Attributes
QVector< QgsInterpolatorVertexData >	mCachedBaseData
	Cached vertex data for input sources. More...
bool	mDataIsCached = false
	Flag that tells if the cache already has been filled. More...
QList< LayerData >	mLayerData
	Information about the input vector layers and the attributes (or z-values) that are used for interpolation. More...

Detailed Description

Interface class for interpolations.

Interpolators take the vertices of a vector layer as base data. The z-Value can be an attribute or the z-coordinates in case of 3D types.

Definition at line 65 of file qgsinterpolator.h.

Member Enumeration Documentation

enum QgsInterpolator::Result

Result of an interpolation operation.

Enumerator
Success	Operation was successful.
Canceled	Operation was manually canceled.
InvalidSource	Operation failed due to invalid source.
FeatureGeometryError	Operation failed due to invalid feature geometry.

Definition at line 86 of file qgsinterpolator.h.

enum QgsInterpolator::SourceType

Describes the type of input data.

Enumerator
SourcePoints	Point source.
SourceStructureLines	Structure lines.
SourceBreakLines	Break lines.

Definition at line 70 of file qgsinterpolator.h.

enum QgsInterpolator::ValueSource

Source for interpolated values from features.

Enumerator
ValueAttribute	Take value from feature's attribute.
ValueZ	Use feature's geometry Z values for interpolation.
ValueM	Use feature's geometry M values for interpolation.

Definition at line 78 of file qgsinterpolator.h.

Constructor & Destructor Documentation

QgsInterpolator::QgsInterpolator

(

const QList< QgsInterpolator::LayerData > &

layerData

)

Definition at line 25 of file qgsinterpolator.cpp.

virtual QgsInterpolator::~QgsInterpolator ( )

virtualdefault

Member Function Documentation

QgsInterpolator::Result QgsInterpolator::cacheBaseData ( QgsFeedback *  feedback = nullptr )

protected

Caches the vertex and value data from the provider.

All the vertex data will be held in virtual memory.

An optional feedback argument may be specified to allow cancellation and progress reports from the cache operation.

Returns

Success in case of success

Definition at line 31 of file qgsinterpolator.cpp.

virtual int QgsInterpolator::interpolatePoint ( double  x, double  y, double &  result, QgsFeedback *  feedback = nullptr  )

pure virtual

Calculates interpolation value for map coordinates x, y.

Parameters

x	x-coordinate (in map units)
y	y-coordinate (in map units)
result	out: interpolation result
feedback	optional feedback object for progress and cancellation support

Returns

0 in case of success

Implemented in QgsTinInterpolator, and QgsIDWInterpolator.

QList<LayerData> QgsInterpolator::layerData ( ) const

inline

Note

not available in Python bindings

Definition at line 121 of file qgsinterpolator.h.

Member Data Documentation

QVector<QgsInterpolatorVertexData> QgsInterpolator::mCachedBaseData

protected

Cached vertex data for input sources.

Definition at line 137 of file qgsinterpolator.h.

bool QgsInterpolator::mDataIsCached = false

protected

Flag that tells if the cache already has been filled.

Definition at line 140 of file qgsinterpolator.h.

QList<LayerData> QgsInterpolator::mLayerData

protected

Information about the input vector layers and the attributes (or z-values) that are used for interpolation.

Definition at line 143 of file qgsinterpolator.h.

---

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

• /build/qgis-3.4.15+24xenial/src/analysis/interpolation/qgsinterpolator.h
• /build/qgis-3.4.15+24xenial/src/analysis/interpolation/qgsinterpolator.cpp