QwtLog10ScaleEngine Class Reference

A scale engine for logarithmic (base 10) scales. More...

#include <qwt_scale_engine.h>

Inheritance diagram for QwtLog10ScaleEngine:

Inheritance graph
[legend]

List of all members.

Public Types

enum  Attribute {
  NoAttribute = 0x00,
  IncludeReference = 0x01,
  Symmetric = 0x02,
  Floating = 0x04,
  Inverted = 0x08
}
typedef QFlags< AttributeAttributes

Public Member Functions

Attributes attributes () const
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
double lowerMargin () const
double reference () const
void setAttribute (Attribute, bool on=true)
void setAttributes (Attributes)
void setMargins (double lower, double upper)
void setReference (double reference)
bool testAttribute (Attribute) const
virtual QwtScaleTransformationtransformation () const
double upperMargin () const

Protected Member Functions

QwtInterval align (const QwtInterval &, double stepSize) const
QwtInterval buildInterval (double v) const
QList< double > buildMajorTicks (const QwtInterval &interval, double stepSize) const
QList< double > buildMinorTicks (const QList< double > &majorTicks, int maxMinMark, double step) const
void buildTicks (const QwtInterval &, double stepSize, int maxMinSteps, QList< double > ticks[QwtScaleDiv::NTickTypes]) const
bool contains (const QwtInterval &, double val) const
double divideInterval (double interval, int numSteps) const
QwtInterval log10 (const QwtInterval &) const
QwtInterval pow10 (const QwtInterval &) const
QList< double > strip (const QList< double > &, const QwtInterval &) const


Detailed Description

A scale engine for logarithmic (base 10) scales.

The step size is measured in *decades* and the major step size will be adjusted to fit the pattern $\left\{ 1,2,3,5\right\} \cdot 10^{n}$, where n is a natural number including zero.

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

Member Typedef Documentation

typedef QFlags<Attribute> QwtScaleEngine::Attributes [inherited]

Layout attributes.


Member Enumeration Documentation

enum QwtScaleEngine::Attribute [inherited]

Layout attributes

See also:
setAttribute(), testAttribute(), reference(), lowerMargin(), upperMargin()
Enumerator:
NoAttribute  No attributes.
IncludeReference  Build a scale which includes the reference() value.
Symmetric  Build a scale which is symmetric to the reference() value.
Floating  The endpoints of the scale are supposed to be equal the outmost included values plus the specified margins (see setMargins()). If this attribute is *not* set, the endpoints of the scale will be integer multiples of the step size.
Inverted  Turn the scale upside down.


Member Function Documentation

QwtInterval QwtLog10ScaleEngine::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

QwtScaleEngine::Attributes QwtScaleEngine::attributes (  )  const [inherited]

Return the scale attributes

See also:
Attribute, setAttributes(), testAttribute()

void QwtLog10ScaleEngine::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.

QwtInterval QwtScaleEngine::buildInterval ( double  v  )  const [protected, inherited]

Build an interval for a value.

In case of v == 0.0 the interval is [-0.5, 0.5], otherwide it is [0.5 * v, 1.5 * v]

QList< double > QwtLog10ScaleEngine::buildMajorTicks ( const QwtInterval interval,
double  stepSize 
) const [protected]

Calculate major ticks for an interval.

Parameters:
interval Interval
stepSize Step size
Returns:
Calculated ticks

QList< double > QwtLog10ScaleEngine::buildMinorTicks ( const QList< double > &  majorTicks,
int  maxMinSteps,
double  stepSize 
) const [protected]

Calculate minor/medium ticks for major ticks.

Parameters:
majorTicks Major ticks
maxMinSteps Maximum number of minor steps
stepSize Step size

void QwtLog10ScaleEngine::buildTicks ( const QwtInterval interval,
double  stepSize,
int  maxMinSteps,
QList< double >  ticks[QwtScaleDiv::NTickTypes] 
) const [protected]

Calculate ticks for an interval.

Parameters:
interval Interval
maxMinSteps Maximum number of minor steps
stepSize Step size
ticks Arrays to be filled with the calculated ticks
See also:
buildMajorTicks(), buildMinorTicks

bool QwtScaleEngine::contains ( const QwtInterval interval,
double  value 
) const [protected, inherited]

Check if an interval "contains" a value

Parameters:
interval Interval
value Value
See also:
QwtScaleArithmetic::compareEps()

double QwtScaleEngine::divideInterval ( double  intervalSize,
int  numSteps 
) const [protected, inherited]

Calculate a step size for an interval size

Parameters:
intervalSize Interval size
numSteps Number of steps
Returns:
Step size

QwtScaleDiv QwtLog10ScaleEngine::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(), QwtLog10ScaleEngine::subDivide()

Implements QwtScaleEngine.

QwtInterval QwtLog10ScaleEngine::log10 ( const QwtInterval interval  )  const [protected]

Return the interval [log10(interval.minValue(), log10(interval.maxValue]

double QwtScaleEngine::lowerMargin (  )  const [inherited]

Returns:
the margin at the lower end of the scale The default margin is 0.
See also:
setMargins()

QwtInterval QwtLog10ScaleEngine::pow10 ( const QwtInterval interval  )  const [protected]

Return the interval [pow10(interval.minValue(), pow10(interval.maxValue]

double QwtScaleEngine::reference (  )  const [inherited]

Returns:
the reference value
See also:
setReference(), setAttribute()

void QwtScaleEngine::setAttribute ( Attribute  attribute,
bool  on = true 
) [inherited]

Change a scale attribute

Parameters:
attribute Attribute to change
on On/Off
See also:
Attribute, testAttribute()

void QwtScaleEngine::setAttributes ( Attributes  attributes  )  [inherited]

Change the scale attribute

Parameters:
attributes Set scale attributes
See also:
Attribute, attributes()

void QwtScaleEngine::setMargins ( double  lower,
double  upper 
) [inherited]

Specify margins at the scale's endpoints.

Parameters:
lower minimum distance between the scale's lower boundary and the smallest enclosed value
upper minimum distance between the scale's upper boundary and the greatest enclosed value
Margins can be used to leave a minimum amount of space between the enclosed intervals and the boundaries of the scale.

Warning:
See also:
upperMargin(), lowerMargin()

void QwtScaleEngine::setReference ( double  r  )  [inherited]

Specify a reference point.

Parameters:
r new reference value
The reference point is needed if options IncludeReference or Symmetric are active. Its default value is 0.0.

See also:
Attribute

QList< double > QwtScaleEngine::strip ( const QList< double > &  ticks,
const QwtInterval interval 
) const [protected, inherited]

Remove ticks from a list, that are not inside an interval

Parameters:
ticks Tick list
interval Interval
Returns:
Stripped tick list

bool QwtScaleEngine::testAttribute ( Attribute  attribute  )  const [inherited]

Check if a attribute is set.

Parameters:
attribute Attribute to be tested
See also:
Attribute, setAttribute()

QwtScaleTransformation * QwtLog10ScaleEngine::transformation (  )  const [virtual]

Return a transformation, for logarithmic (base 10) scales

Implements QwtScaleEngine.

double QwtScaleEngine::upperMargin (  )  const [inherited]

Returns:
the margin at the upper end of the scale The default margin is 0.
See also:
setMargins()


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