QwtLogTransform Class Reference

Logarithmic transformation. More...

#include <qwt_transform.h>

Inheritance diagram for QwtLogTransform:

Public Member Functions
	QwtLogTransform ()
	Constructor.
virtual	~QwtLogTransform ()
	Destructor.
virtual double	transform (double value) const
virtual double	invTransform (double value) const
virtual double	bounded (double value) const
virtual QwtTransform *	copy () const
Public Attributes
QT_STATIC_CONST double	LogMin = 1.0e-150
	Smallest allowed value for logarithmic scales: 1.0e-150.
QT_STATIC_CONST double	LogMax = 1.0e150
	Largest allowed value for logarithmic scales: 1.0e150.

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Detailed Description

Logarithmic transformation.

QwtLogTransform modifies the values using log() and exp().

Note:

In the calculations of QwtScaleMap the base of the log function has no effect on the mapping. So QwtLogTransform can be used for log2(), log10() or any other logarithmic scale.

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Member Function Documentation

double QwtLogTransform::bounded

(

double

value

)

const [virtual]

Parameters:

value

Value to be bounded

Returns:

qBound( LogMin, value, LogMax )

Reimplemented from QwtTransform.

QwtTransform * QwtLogTransform::copy

(

)

const [virtual]

Returns:

Clone of the transformation

Implements QwtTransform.

double QwtLogTransform::invTransform

(

double

value

)

const [virtual]

Parameters:

value

Value to be transformed

Returns:

exp( value )

Implements QwtTransform.

double QwtLogTransform::transform

(

double

value

)

const [virtual]

Parameters:

value

Value to be transformed

Returns:

log( value )

Implements QwtTransform.

List of all members.