QwtScaleTransformation Class Reference

List of all members.

Detailed Description

Operations for linear or logarithmic (base 10) transformations.

Definition at line 19 of file 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 QwtScaleTransformationcopy () const


Member Enumeration Documentation

enum QwtScaleTransformation::Type

Enumerator:
Linear 
Log10 
Other 

Definition at line 22 of file qwt_scale_map.h.


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.

References Log10.

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.

References Log10.

Referenced by QwtScaleMap::invTransform().


Generated on Sun Jul 22 11:26:57 2007 for Qwt User's Guide by  doxygen 1.5.2