Quantum GIS API Documentation
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00001 /*************************************************************************** 00002 qgsslopefilter.h - description 00003 -------------------------------- 00004 begin : August 7th, 2009 00005 copyright : (C) 2009 by Marco Hugentobler 00006 email : marco dot hugentobler at karto dot baug dot ethz dot ch 00007 ***************************************************************************/ 00008 00009 /*************************************************************************** 00010 * * 00011 * This program is free software; you can redistribute it and/or modify * 00012 * it under the terms of the GNU General Public License as published by * 00013 * the Free Software Foundation; either version 2 of the License, or * 00014 * (at your option) any later version. * 00015 * * 00016 ***************************************************************************/ 00017 00018 #include "qgsslopefilter.h" 00019 00020 QgsSlopeFilter::QgsSlopeFilter( const QString& inputFile, const QString& outputFile, const QString& outputFormat ) 00021 : QgsDerivativeFilter( inputFile, outputFile, outputFormat ) 00022 { 00023 00024 } 00025 00026 QgsSlopeFilter::~QgsSlopeFilter() 00027 { 00028 00029 } 00030 00031 float QgsSlopeFilter::processNineCellWindow( float* x11, float* x21, float* x31, 00032 float* x12, float* x22, float* x32, float* x13, float* x23, float* x33 ) 00033 { 00034 float derX = calcFirstDerX( x11, x21, x31, x12, x22, x32, x13, x23, x33 ); 00035 float derY = calcFirstDerY( x11, x21, x31, x12, x22, x32, x13, x23, x33 ); 00036 00037 if ( derX == mOutputNodataValue || derY == mOutputNodataValue ) 00038 { 00039 return mOutputNodataValue; 00040 } 00041 00042 return atan( sqrt( derX * derX + derY * derY ) ) * 180.0 / M_PI; 00043 } 00044