178 lines
3.4 KiB
C++
178 lines
3.4 KiB
C++
/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
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* Qwt Widget Library
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* Copyright (C) 1997 Josef Wilgen
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* Copyright (C) 2002 Uwe Rathmann
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the Qwt License, Version 1.0
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*****************************************************************************/
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#include "qwt_transform.h"
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#include "qwt_math.h"
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#if QT_VERSION < 0x040601
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#define qExp(x) ::exp(x)
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#endif
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#if QT_VERSION >= 0x050400
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//! Smallest allowed value for logarithmic scales: 1.0e-150
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const double QwtLogTransform::LogMin = 1.0e-150;
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//! Largest allowed value for logarithmic scales: 1.0e150
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const double QwtLogTransform::LogMax = 1.0e150;
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#else
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//! Smallest allowed value for logarithmic scales: 1.0e-150
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QT_STATIC_CONST_IMPL double QwtLogTransform::LogMin = 1.0e-150;
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//! Largest allowed value for logarithmic scales: 1.0e150
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QT_STATIC_CONST_IMPL double QwtLogTransform::LogMax = 1.0e150;
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#endif
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//! Constructor
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QwtTransform::QwtTransform()
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{
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}
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//! Destructor
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QwtTransform::~QwtTransform()
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{
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}
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/*!
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\param value Value to be bounded
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\return value unmodified
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*/
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double QwtTransform::bounded( double value ) const
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{
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return value;
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}
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//! Constructor
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QwtNullTransform::QwtNullTransform():
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QwtTransform()
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{
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}
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//! Destructor
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QwtNullTransform::~QwtNullTransform()
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{
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}
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/*!
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\param value Value to be transformed
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\return value unmodified
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*/
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double QwtNullTransform::transform( double value ) const
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{
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return value;
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}
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/*!
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\param value Value to be transformed
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\return value unmodified
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*/
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double QwtNullTransform::invTransform( double value ) const
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{
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return value;
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}
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//! \return Clone of the transformation
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QwtTransform *QwtNullTransform::copy() const
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{
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return new QwtNullTransform();
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}
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//! Constructor
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QwtLogTransform::QwtLogTransform():
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QwtTransform()
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{
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}
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//! Destructor
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QwtLogTransform::~QwtLogTransform()
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{
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}
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/*!
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\param value Value to be transformed
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\return log( value )
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*/
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double QwtLogTransform::transform( double value ) const
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{
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return ::log( value );
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}
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/*!
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\param value Value to be transformed
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\return exp( value )
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*/
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double QwtLogTransform::invTransform( double value ) const
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{
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return qExp( value );
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}
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/*!
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\param value Value to be bounded
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\return qBound( LogMin, value, LogMax )
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*/
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double QwtLogTransform::bounded( double value ) const
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{
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return qBound( LogMin, value, LogMax );
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}
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//! \return Clone of the transformation
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QwtTransform *QwtLogTransform::copy() const
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{
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return new QwtLogTransform();
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}
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/*!
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Constructor
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\param exponent Exponent
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*/
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QwtPowerTransform::QwtPowerTransform( double exponent ):
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QwtTransform(),
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d_exponent( exponent )
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{
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}
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//! Destructor
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QwtPowerTransform::~QwtPowerTransform()
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{
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}
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/*!
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\param value Value to be transformed
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\return Exponentiation preserving the sign
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*/
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double QwtPowerTransform::transform( double value ) const
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{
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if ( value < 0.0 )
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return -qPow( -value, 1.0 / d_exponent );
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else
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return qPow( value, 1.0 / d_exponent );
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}
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/*!
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\param value Value to be transformed
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\return Inverse exponentiation preserving the sign
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*/
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double QwtPowerTransform::invTransform( double value ) const
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{
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if ( value < 0.0 )
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return -qPow( -value, d_exponent );
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else
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return qPow( value, d_exponent );
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}
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//! \return Clone of the transformation
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QwtTransform *QwtPowerTransform::copy() const
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{
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return new QwtPowerTransform( d_exponent );
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}
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