QgsMeshCalculator Class Reference

Performs mesh layer calculations. More...

#include <qgsmeshcalculator.h>

Public Types
enum	Result {   Success = 0, Canceled, CreateOutputError, InputLayerError,   ParserError, InvalidDatasets, EvaluateError, MemoryError }
	Result of the calculation. More...

Public Member Functions
	QgsMeshCalculator (const QString &formulaString, const QString &outputFile, const QgsRectangle &outputExtent, double startTime, double endTime, QgsMeshLayer *layer)
	Creates calculator with bounding box (rectangular) mask. More...
	QgsMeshCalculator (const QString &formulaString, const QString &outputFile, const QgsGeometry &outputMask, double startTime, double endTime, QgsMeshLayer *layer)
	Creates calculator with geometry mask. More...
Result	processCalculation (QgsFeedback *feedback=nullptr)
	Starts the calculation, writes new dataset group to file and adds it to the mesh layer. More...

Static Public Member Functions
static Result	expression_valid (const QString &formulaString, QgsMeshLayer *layer)
	Returns whether formula is valid for particular mesh layer. More...

Detailed Description

Performs mesh layer calculations.

Mesh calculator can do various mathematical operations between dataset groups from a single mesh layer. Resulting dataset group is added to the mesh layer. Result can be filtered by extent or a vector layer mask spatially and by selection of times.

Note: only dataset groups defined on vertices are implemented and supported

Since

QGIS 3.6

Definition at line 49 of file qgsmeshcalculator.h.

Member Enumeration Documentation

Result

enum QgsMeshCalculator::Result

Result of the calculation.

Enumerator
Success	Calculation successful.
Canceled	Calculation canceled.
CreateOutputError	Error creating output data file.
InputLayerError	Error reading input layer.
ParserError	Error parsing formula.
InvalidDatasets	Datasets with different time outputs or not part of the mesh.
EvaluateError	Error during evaluation.
MemoryError	Error allocating memory for result.

Definition at line 54 of file qgsmeshcalculator.h.

Constructor & Destructor Documentation

QgsMeshCalculator() [1/2]

QgsMeshCalculator::QgsMeshCalculator	(	const QString &	formulaString,
		const QString &	outputFile,
		const QgsRectangle &	outputExtent,
		double	startTime,
		double	endTime,
		QgsMeshLayer *	layer
	)

Creates calculator with bounding box (rectangular) mask.

Parameters

formulaString	formula/expression to evaluate. Consists of dataset group names, operators and numbers
outputFile	file to store the resulting dataset group data
outputExtent	spatial filter defined by rectangle
startTime	time filter defining the starting dataset
endTime	time filter defining the ending dataset
layer	mesh layer with dataset groups references in formulaString

Definition at line 28 of file qgsmeshcalculator.cpp.

QgsMeshCalculator() [2/2]

QgsMeshCalculator::QgsMeshCalculator	(	const QString &	formulaString,
		const QString &	outputFile,
		const QgsGeometry &	outputMask,
		double	startTime,
		double	endTime,
		QgsMeshLayer *	layer
	)

Creates calculator with geometry mask.

Parameters

formulaString	formula/expression to evaluate. Consists of dataset group names, operators and numbers
outputFile	file to store the resulting dataset group data
outputMask	spatial filter defined by geometry
startTime	time filter defining the starting dataset
endTime	time filter defining the ending dataset
layer	mesh layer with dataset groups references in formulaString

Definition at line 41 of file qgsmeshcalculator.cpp.

Member Function Documentation

expression_valid()

QgsMeshCalculator::Result QgsMeshCalculator::expression_valid ( const QString &  formulaString, QgsMeshLayer *  layer  )

static

Returns whether formula is valid for particular mesh layer.

Parameters

formulaString	formula/expression to evaluate. Consists of dataset group names, operators and numbers
layer	mesh layer with dataset groups references in formulaString

Returns

QgsMeshCalculator::Success in case of success

Definition at line 57 of file qgsmeshcalculator.cpp.

processCalculation()

QgsMeshCalculator::Result QgsMeshCalculator::processCalculation

(

QgsFeedback *

feedback = nullptr

)

Starts the calculation, writes new dataset group to file and adds it to the mesh layer.

Parameters

feedback

The optional feedback argument for progress reporting and cancellation support

Returns

QgsMeshCalculator::Success in case of success

Definition at line 78 of file qgsmeshcalculator.cpp.

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

• /tmp/buildd/qgis-3.8.0+99unstable/src/analysis/mesh/qgsmeshcalculator.h
• /tmp/buildd/qgis-3.8.0+99unstable/src/analysis/mesh/qgsmeshcalculator.cpp