Raster calculator class. More...

#include <qgsrastercalculator.h>

Collaboration diagram for QgsRasterCalculator:

Public Member Functions
	QgsRasterCalculator (const QString &formulaString, const QString &outputFile, const QString &outputFormat, const QgsRectangle &outputExtent, int nOutputColumns, int nOutputRows, const QVector< QgsRasterCalculatorEntry > &rasterEntries)
	~QgsRasterCalculator ()
int	processCalculation (QProgressDialog *p=0)
	Starts the calculation and writes new raster.

Private Member Functions
	QgsRasterCalculator ()
GDALDriverH	openOutputDriver ()
	Opens the output driver and tests if it supports the creation of a new dataset.
GDALDatasetH	openOutputFile (GDALDriverH outputDriver)
	Opens the output file and sets the same geotransform and CRS as the input data.
void	readRasterPart (double targetGeotransform, int xOffset, int yOffset, int nCols, int nRows, double sourceTransform, GDALRasterBandH sourceBand, float *rasterBuffer)
	Reads raster pixels from a dataset/band.
bool	transformationsEqual (double t1, double t2) const
	Compares two geotransformations (six parameter double arrays.
void	outputGeoTransform (double *transform) const
	Sets gdal 6 parameters array from mOutputRectangle, mNumOutputColumns, mNumOutputRows.

Private Attributes
QString	mFormulaString
QString	mOutputFile
QString	mOutputFormat
QgsRectangle	mOutputRectangle
	Output raster extent.
int	mNumOutputColumns
	Number of output columns.
int	mNumOutputRows
	Number of output rows.
QVector< QgsRasterCalculatorEntry >	mRasterEntries

Detailed Description

Raster calculator class.

Definition at line 39 of file qgsrastercalculator.h.

Constructor & Destructor Documentation

QgsRasterCalculator::QgsRasterCalculator	(	const QString &	formulaString,
		const QString &	outputFile,
		const QString &	outputFormat,
		const QgsRectangle &	outputExtent,
		int	nOutputColumns,
		int	nOutputRows,
		const QVector< QgsRasterCalculatorEntry > &	rasterEntries
	)

Definition at line 37 of file qgsrastercalculator.cpp.

QgsRasterCalculator::~QgsRasterCalculator ( )

Definition at line 43 of file qgsrastercalculator.cpp.

QgsRasterCalculator::QgsRasterCalculator ( )

private

Definition at line 251 of file qgsrastercalculator.cpp.

Member Function Documentation

GDALDriverH QgsRasterCalculator::openOutputDriver ( )

private

Opens the output driver and tests if it supports the creation of a new dataset.

Returns: NULL on error and the driver handle on success

Definition at line 255 of file qgsrastercalculator.cpp.

References mOutputFormat.

Referenced by processCalculation().

GDALDatasetH QgsRasterCalculator::openOutputFile ( GDALDriverH outputDriver )

private

Opens the output file and sets the same geotransform and CRS as the input data.

Returns: the output dataset or NULL in case of error

Definition at line 276 of file qgsrastercalculator.cpp.

References mNumOutputColumns, mNumOutputRows, mOutputFile, outputGeoTransform(), and TO8F.

Referenced by processCalculation().

void QgsRasterCalculator::outputGeoTransform ( double * transform ) const

private

Sets gdal 6 parameters array from mOutputRectangle, mNumOutputColumns, mNumOutputRows.

Parameters

transform double[6] array that receives the GDAL parameters

Definition at line 403 of file qgsrastercalculator.cpp.

References QgsRectangle::height(), mNumOutputColumns, mNumOutputRows, mOutputRectangle, QgsRectangle::width(), QgsRectangle::xMinimum(), and QgsRectangle::yMaximum().

Referenced by openOutputFile(), and processCalculation().

int QgsRasterCalculator::processCalculation ( QProgressDialog * p = 0 )

Starts the calculation and writes new raster.

Parameters

p	progress bar (or 0 if called from non-gui code)

Returns: 0 in case of success

Definition at line 47 of file qgsrastercalculator.cpp.

References QgsCoordinateReferenceSystem::authid(), QgsRasterCalcNode::calculate(), QgsMapLayer::crs(), QgsRasterMatrix::data(), QgsRasterMatrix::isNumber(), mFormulaString, mNumOutputColumns, mNumOutputRows, mOutputFile, mRasterEntries, QgsRasterMatrix::nodataValue(), QgsRasterMatrix::number(), openOutputDriver(), openOutputFile(), outputGeoTransform(), QgsRasterCalcNode::parseRasterCalcString(), readRasterPart(), TO8, TO8F, and QgsCoordinateReferenceSystem::toWkt().

void QgsRasterCalculator::readRasterPart	(	double *	targetGeotransform,
		int	xOffset,
		int	yOffset,
		int	nCols,
		int	nRows,
		double *	sourceTransform,
		GDALRasterBandH	sourceBand,
		float *	rasterBuffer
	)

private

Reads raster pixels from a dataset/band.

Parameters

targetGeotransform	transformation parameters of the requested raster array (not necessarily the same as the transform of the source dataset)
xOffset	x offset
yOffset	y offset
nCols	number of columns
nRows	number of rows
sourceTransform	source transformation
sourceBand	source band
rasterBuffer	raster buffer