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QwtScaleTransformation(3) Qwt User's Guide QwtScaleTransformation(3)

NAME

QwtScaleTransformation -

SYNOPSIS

#include <qwt_scale_map.h>

Public Types


enum Type { Linear, Log10, Other }

Public Member Functions


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

Detailed Description

Operations for linear or logarithmic (base 10) transformations.

Member Function Documentation

double QwtScaleTransformation::invXForm (doublep, doublep1, doublep2, doubles1, doubles2) const [virtual]

Transform a value from the coordinate system of the paint device into the coordinate system of a scale. Parameters:

p Value related to the coordinate system of the paint device
p1 First border of the coordinate system of the paint device
p2 Second border of the coordinate system of the paint device
s1 First border of the coordinate system of the scale
s2 Second border of the coordinate system of the scale

Returns:

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

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

Returns:

Transformation type

double QwtScaleTransformation::xForm (doubles, doubles1, doubles2, doublep1, doublep2) const [virtual]

Transform a value from the coordinate system of a scale into the coordinate system of the paint device. Parameters:

s Value related to the coordinate system of the scale
s1 First border of the coordinate system of the scale
s2 Second border of the coordinate system of the scale
p1 First border of the coordinate system of the paint device
p2 Second border of the coordinate system of the paint device

Returns:

p1 + (p2 - p1) / (s2 - s1) * (s - s1);
p1 + (p2 - p1) / log(s2 / s1) * log(s / s1);

Author

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Tue Nov 20 2012 Version 5.2.3