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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:
linear mapping:
s1 + ( s2 - s1 ) / ( p2 - p1 ) * ( p - p1 );
log10 mapping:
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:
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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Version 5.2.3 Tue Nov 20 2012 QwtScaleTransformation(3)