NAME

       QwtLogScaleEngine - A scale engine for logarithmic scales.

SYNOPSIS

       #include <qwt_scale_engine.h>

       Inherits QwtScaleEngine.

   Public Member Functions
       QwtLogScaleEngine (uint base=10)
       virtual ~QwtLogScaleEngine ()
           Destructor.
       virtual void autoScale (int maxNumSteps, double &x1, double &x2, double &stepSize) const
       virtual QwtScaleDiv divideScale (double x1, double x2, int maxMajorSteps, int
           maxMinorSteps, double stepSize=0.0) const
           Calculate a scale division for an interval.

   Protected Member Functions
       QwtInterval align (const QwtInterval &, double stepSize) const
           Align an interval to a step size.
       void buildTicks (const QwtInterval &, double stepSize, int maxMinorSteps, QList< double >
           ticks[QwtScaleDiv::NTickTypes]) const
           Calculate ticks for an interval.
       QList< double > buildMajorTicks (const QwtInterval &interval, double stepSize) const
           Calculate major ticks for an interval.
       void buildMinorTicks (const QList< double > &majorTicks, int maxMinorSteps, double
           stepSize, QList< double > &minorTicks, QList< double > &mediumTicks) const
           Calculate minor/medium ticks for major ticks.

   Additional Inherited Members

Detailed Description

       A scale engine for logarithmic scales.

       The step size is mightred in decades and the major step size will be adjusted to fit the
       pattern $t 1,2,3,5

       Warning:
           the step size as well as the margins are measured in decades.

Constructor & Destructor Documentation

   QwtLogScaleEngine::QwtLogScaleEngine (uint base = 10)
       Constructor

       Parameters:
           base Base of the scale engine

       See also:
           setBase()

Member Function Documentation

   QwtInterval QwtLogScaleEngine::align (const QwtInterval & 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 QwtLogScaleEngine::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:
           QwtScaleEngine::setAttribute()

       Implements QwtScaleEngine.

   QList< double > QwtLogScaleEngine::buildMajorTicks (const QwtInterval & interval, double
       stepSize) const [protected]
       Calculate major ticks for an interval.

       Parameters:
           interval Interval
           stepSize Step size

       Returns:
           Calculated ticks

   void QwtLogScaleEngine::buildMinorTicks (const QList< double > & majorTicks, int
       maxMinorSteps, double stepSize, QList< double > & minorTicks, QList< double > &
       mediumTicks) const [protected]
       Calculate minor/medium ticks for major ticks.

       Parameters:
           majorTicks Major ticks
           maxMinorSteps Maximum number of minor steps
           stepSize Step size
           minorTicks Array to be filled with the calculated minor ticks
           mediumTicks Array to be filled with the calculated medium ticks

   void QwtLogScaleEngine::buildTicks (const QwtInterval & interval, double stepSize, int
       maxMinorSteps, QList< double > ticks[QwtScaleDiv::NTickTypes]) const [protected]
       Calculate ticks for an interval.

       Parameters:
           interval Interval
           maxMinorSteps Maximum number of minor steps
           stepSize Step size
           ticks Arrays to be filled with the calculated ticks

       See also:
           buildMajorTicks(), buildMinorTicks

   QwtScaleDiv QwtLogScaleEngine::divideScale (double x1, double x2, int maxMajorSteps, int
       maxMinorSteps, double stepSize = 0.0) const [virtual]
       Calculate a scale division for an interval.

       Parameters:
           x1 First interval limit
           x2 Second interval limit
           maxMajorSteps Maximum for the number of major steps
           maxMinorSteps Maximum number of minor steps
           stepSize Step size. If stepSize == 0, the engine calculates one.

       Returns:
           Calculated scale division

       Implements QwtScaleEngine.

Author

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