Qwt User's Guide: QwtScaleTransformation Class Reference

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QwtScaleTransformation Class Reference

Operations for linear or logarithmic (base 10) transformations. More...

#include <qwt_scale_map.h>

List of all members.

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:
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;
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:
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)
Generated on Wed Sep 2 18:37:27 2009 for Qwt User's Guide by  doxygen 1.6.1
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