Quantum GIS API Documentation
1.7.5-Wroclaw
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Calculates aspect values in a window of 3x3 cells based on first order derivatives in x- and y- directions. More...
#include <qgsaspectfilter.h>
Public Member Functions | |
QgsAspectFilter (const QString &inputFile, const QString &outputFile, const QString &outputFormat) | |
~QgsAspectFilter () | |
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QgsDerivativeFilter (const QString &inputFile, const QString &outputFile, const QString &outputFormat) | |
virtual | ~QgsDerivativeFilter () |
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QgsNineCellFilter (const QString &inputFile, const QString &outputFile, const QString &outputFormat) | |
Constructor that takes input file, output file and output format (GDAL string) | |
virtual | ~QgsNineCellFilter () |
int | processRaster (QProgressDialog *p) |
Starts the calculation, reads from mInputFile and stores the result in mOutputFile. |
Protected Member Functions | |
float | processNineCellWindow (float *x11, float *x21, float *x31, float *x12, float *x22, float *x32, float *x13, float *x23, float *x33) |
Calculates output value from nine input values. | |
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float | calcFirstDerX (float *x11, float *x21, float *x31, float *x12, float *x22, float *x32, float *x13, float *x23, float *x33) |
Calculates the first order derivative in x-direction according to Horn (1981) | |
float | calcFirstDerY (float *x11, float *x21, float *x31, float *x12, float *x22, float *x32, float *x13, float *x23, float *x33) |
Calculates the first order derivative in y-direction according to Horn (1981) |
Calculates aspect values in a window of 3x3 cells based on first order derivatives in x- and y- directions.
Direction is clockwise starting from north
Definition at line 24 of file qgsaspectfilter.h.
QgsAspectFilter::QgsAspectFilter | ( | const QString & | inputFile, |
const QString & | outputFile, | ||
const QString & | outputFormat | ||
) |
Definition at line 20 of file qgsaspectfilter.cpp.
QgsAspectFilter::~QgsAspectFilter | ( | ) |
Definition at line 26 of file qgsaspectfilter.cpp.
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protectedvirtual |
Calculates output value from nine input values.
The input values and the output value can be equal to the \ nodata value if not present or outside of the border. Must be implemented by subclasses
Implements QgsDerivativeFilter.
Definition at line 31 of file qgsaspectfilter.cpp.
References QgsDerivativeFilter::calcFirstDerX(), QgsDerivativeFilter::calcFirstDerY(), M_PI, and QgsNineCellFilter::mOutputNodataValue.