54 lines
1.2 KiB
C++
54 lines
1.2 KiB
C++
/*****************************************************************************
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* Qwt Examples - Copyright (C) 2002 Uwe Rathmann
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* This file may be used under the terms of the 3-clause BSD License
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*****************************************************************************/
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#include "Plot.h"
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#include <QwtMath>
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#include <QApplication>
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static inline double randomValue()
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{
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// a number between [ 0.0, 1.0 ]
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return ( qwtRand() % 100000 ) / 100000.0;
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}
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class ScatterPlot : public Plot
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{
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public:
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ScatterPlot()
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{
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setTitle( "Scatter Plot" );
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// a million points
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const int numPoints = 100000;
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QPolygonF samples;
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samples.reserve( numPoints );
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for ( int i = 0; i < numPoints; i++ )
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{
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const double x = randomValue() * 24.0 + 1.0;
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const double y = std::log( 10.0 * ( x - 1.0 ) + 1.0 )
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* ( randomValue() * 0.5 + 0.9 );
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samples += QPointF( x, y );
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}
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setSamples( samples );
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}
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};
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int main( int argc, char* argv[] )
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{
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QApplication app( argc, argv );
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ScatterPlot plot;
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plot.resize( 800, 600 );
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plot.show();
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return app.exec();
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}
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