Qwt User's Guide: QwtLinearScaleEngine Class Reference

Qwt User's Guide 5.2.3

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Public Member Functions | Protected Member Functions
QwtLinearScaleEngine Class Reference

`#include <qwt_scale_engine.h>`

Inheritance diagram for QwtLinearScaleEngine:
[legend]

List of all members.

## Public Member Functions
virtual void | autoScale (int maxSteps, double &x1, double &x2, double &stepSize) const
virtual QwtScaleDiv | divideScale (double x1, double x2, int numMajorSteps, int numMinorSteps, double stepSize=0.0) const
virtual QwtScaleTransformation * | transformation () const
Public Member Functions inherited from QwtScaleEngine
| QwtScaleEngine ()
virtual | ~QwtScaleEngine ()
int | attributes () const
double | lowerMargin () const
double | reference () const
void | setAttribute (Attribute, bool on=true)
void | setAttributes (int)
void | setMargins (double lower, double upper)
void | setReference (double reference)
bool | testAttribute (Attribute) const
double | upperMargin () const

## Protected Member Functions
QwtDoubleInterval | align (const QwtDoubleInterval &, double stepSize) const
Protected Member Functions inherited from QwtScaleEngine
QwtDoubleInterval | buildInterval (double v) const
bool | contains (const QwtDoubleInterval &, double val) const
double | divideInterval (double interval, int numSteps) const
QwtValueList | strip (const QwtValueList &, const QwtDoubleInterval &) const

## Additional Inherited Members
Public Types inherited from QwtScaleEngine
enum | Attribute { NoAttribute = 0, IncludeReference = 1, Symmetric = 2, Floating = 4, Inverted = 8 }

## Detailed Description

A scale engine for linear scales.

The step size will fit into the pattern , where n is an integer.

## Member Function Documentation

QwtDoubleInterval QwtLinearScaleEngine::align | ( | const QwtDoubleInterval & | interval,
|  | double | stepSize
| ) |  | const
| protected

Align an interval to a step size.

The limits of an interval are aligned that both are integer multiples of the step size.

Parameters:

  interval | Interval
  stepSize | Step size

Returns:
  Aligned interval

void QwtLinearScaleEngine::autoScale | ( | int | maxNumSteps,
|  | double & | x1,
|  | double & | x2,
|  | double & | stepSize
| ) |  | const
| virtual

Align and divide an interval

Parameters:

  maxNumSteps | Max. number of steps
  x1 | First limit of the interval (In/Out)
  x2 | Second limit of the interval (In/Out)
  stepSize | Step size (Out)

See also:
  setAttribute()

Implements QwtScaleEngine.

QwtScaleDiv QwtLinearScaleEngine::divideScale | ( | double | x1,
|  | double | x2,
|  | int | maxMajSteps,
|  | int | maxMinSteps,
|  | double | stepSize = `0.0`
| ) |  | const
| virtual

Calculate a scale division.

Parameters:

  x1 | First interval limit
  x2 | Second interval limit
  maxMajSteps | Maximum for the number of major steps
  maxMinSteps | Maximum number of minor steps
  stepSize | Step size. If stepSize == 0, the scaleEngine calculates one.

See also:
  QwtScaleEngine::stepSize(), QwtScaleEngine::subDivide()

Implements QwtScaleEngine.

QwtScaleTransformation * QwtLinearScaleEngine::transformation | ( |  | ) | const
| virtual

Return a transformation, for linear scales

Implements QwtScaleEngine.