QwtScaleTransformation

Langue: en

Autres versions - même langue

Version: 159789 (fedora - 05/07/09)

Section: 3 (Bibliothèques de fonctions)

Sommaire

NAME

QwtScaleTransformation -

SYNOPSIS


Detailed Description

Operations for linear or logarithmic (base 10) transformations.

Definition at line 19 of file qwt_scale_map.h.

Public Types


enum Type { RubberBand, Text, 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

Constructor & Destructor Documentation

QwtScaleTransformation::QwtScaleTransformation (Type type)

Constructor for a linear transformation.

Definition at line 16 of file qwt_scale_map.cpp.

References QwtScaleTransformation().

Referenced by QwtScaleTransformation().

Member Function Documentation

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

Transform a value between 2 linear intervals.

Parameters:

x value related to the interval [x1, x2]
x1 first border of source interval
x2 first border of source interval
y1 first border of target interval
y2 first border of target interval

Returns:

linear mapping:
y1 + (y2 - y1) / (x2 - x1) * (x - x1)
log10 mapping:
p1 + (p2 - p1) / log(s2 / s1) * log(x / s1)

Definition at line 47 of file qwt_scale_map.cpp.

Referenced by QwtScaleMap::xTransform().

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:

x value related to the linear interval [p1, p2]
p1 first border of linear interval
p2 first border of linear interval
s1 first border of logarithmic interval
s2 first border of logarithmic interval

Returns:

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

Definition at line 70 of file qwt_scale_map.cpp.

Referenced by QwtScaleMap::invTransform().

Author

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