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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 Member Functions

 QwtScaleTransformation ()
 QwtScaleTransformation (double(*xForm)(double x, double s1, double s2, double p1, double p2, void *), double(*invXForm)(double x, double p1, double p2, double s1, double s2, void *))

Static Public Member Functions

static double linearXForm (double x, double s1, double s2, double p1, double p2, void *)
static double log10XForm (double x, double s1, double s2, double p1, double p2, void *)
static double log10InvXForm (double x, double p1, double p2, double s1, double s2, void *)

Public Attributes

double(* xForm )(double x, double s1, double s2, double p1, double p2, void *)
double(* invXForm )(double y, double p1, double p2, double s1, double s2, void *)


Member Function Documentation

double QwtScaleTransformation::linearXForm double  x,
double  x1,
double  x2,
double  y1,
double  y2,
void * 
[static]
 

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)

Definition at line 45 of file qwt_scale_map.cpp.

Referenced by QwtScaleMap::setTransformation(), QwtLinearScaleEngine::transformation(), and QwtScaleMap::xTransform().

double QwtScaleTransformation::log10InvXForm double  x,
double  p1,
double  p2,
double  s1,
double  s2,
void * 
[static]
 

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 87 of file qwt_scale_map.cpp.

Referenced by QwtScaleMap::setTransformation(), and QwtLog10ScaleEngine::transformation().

double QwtScaleTransformation::log10XForm double  x,
double  s1,
double  s2,
double  p1,
double  p2,
void * 
[static]
 

Transform a value from a logarithmic to a linear interval.

Parameters:
x value related to the logarithmic interval [s1, s2]
s1 first border of logarithmic interval
s2 first border of logarithmic interval
p1 first border of linear interval
p2 first border of linear interval
Returns:
p1 + (p2 - p1) / log(s2 / s1) * log(x / s1)

Definition at line 67 of file qwt_scale_map.cpp.

Referenced by QwtScaleMap::setScaleInterval(), QwtScaleMap::setTransformation(), QwtLog10ScaleEngine::transformation(), and QwtScaleMap::xTransform().


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