QwtScaleTransformation(3)

NAME
QwtScaleTransformation -

Operations for linear or logarithmic (base 10) transformations.

SYNOPSIS

#include <qwt_scale_map.h>

  Public Types
enum Type { Linear, Log10, Other }

  Public Member Functions
QwtScaleTransformation (Type type)
virtual ~QwtScaleTransformation ()
virtual double xForm (double x, double s1, double s2, double p1, double p2) const
virtual double invXForm (double x, double s1, double s2, double p1, double p2) const
Type type () const
virtual QwtScaleTransformation * copy () const

Detailed Description

Operations for linear or logarithmic (base 10) transformations.

Constructor & Destructor Documentation

  QwtScaleTransformation::QwtScaleTransformation (Type type)

Constructor for a linear transformation.

  QwtScaleTransformation::~QwtScaleTransformation () [virtual]

Destructor.

Member Function Documentation

  QwtScaleTransformation * QwtScaleTransformation::copy () const [virtual]

Create a clone of the transformation.

  double QwtScaleTransformation::invXForm (double p, double p1, double p2, double s1, double s2) const [virtual]

Transform a value from a linear to a logarithmic interval. Parameters:
    p value related to the linear interval [p1, p2]
    p1 first border of linear interval
    p2 second border of linear interval
    s1 first border of logarithmic interval
    s2 second border of logarithmic interval

Returns:

    exp((p - p1) / (p2 - p1) * log(s2 / s1)) * s1;

  QwtScaleTransformation::Type QwtScaleTransformation::type () const [inline] Returns:
    Transformation type

  double QwtScaleTransformation::xForm (double s, double s1, double s2, double p1, double p2) const [virtual]

Transform a value between 2 linear intervals. Parameters:
    s value related to the interval [s1, s2]
    s1 first border of scale interval
    s2 second border of scale interval
    p1 first border of target interval
    p2 second border of target interval

Returns:

    linear mapping:
        p1 + (p2 - p1) / (s2 - s1) * (s - s1)

    log10 mapping:
        p1 + (p2 - p1) / log(s2 / s1) * log(s / s1)

Author

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