PolarCoord class
The specification of a polar coordinate.
In a polar coordinate, dimensions are assigned to angle and radius. The angles are in radians.
The plane of a polar coordinate is defined not only by the coordinate region, but also the starts and ends of angle and radius dimensions on canvas, which are defined by startAngle, endAngle, startRadius, and endRadius.
Constructors

PolarCoord({double? startAngle, double? endAngle, double? startRadius, double? endRadius, List<
double> ? angleRange, EventUpdater<List< ? angleRangeUpdater, List<double> >double> ? radiusRange, EventUpdater<List< ? radiusRangeUpdater, int? dimCount, double? dimFill, bool? transposed, Color? color, Gradient? gradient})double> >  Creates a polar coord.
Properties

angleRange
↔ List<
double> ? 
Range ratio of coordinate angle to plane angle.
getter/setter pair

angleRangeUpdater
↔ EventUpdater<
List< ?double> > 
Event updater of angleRange.
getter/setter pair
 color ↔ Color?

The color of this coordinate region.
getter/setter pairinherited
 dimCount ↔ int?

The count of coordinate dimensions.
getter/setter pairinherited
 dimFill ↔ double?

The position value to fill the domain dimension when dimCount is 1.
getter/setter pairinherited
 endAngle ↔ double?

The end angle of the plane.
getter/setter pair
 endRadius ↔ double?

The end radius ratio of the plane to the minimum side of coordinate region.
getter/setter pair
 gradient ↔ Gradient?

The gradient of this coordinate region.
getter/setter pairinherited
 hashCode → int

The hash code for this object.
no setterinherited
 layer ↔ int?

The layer of this coordinate region background.
getter/setter pairinherited

radiusRange
↔ List<
double> ? 
Range ratio of coordinate radius to plane radius.
getter/setter pair

radiusRangeUpdater
↔ EventUpdater<
List< ?double> > 
Event updater of radiusRange.
getter/setter pair
 runtimeType → Type

A representation of the runtime type of the object.
no setterinherited
 startAngle ↔ double?

The start angle of the plane.
getter/setter pair
 startRadius ↔ double?

The start radius ratio of the plane to the minimum side of coordinate region.
getter/setter pair
 transposed ↔ bool?

Weither to transpose domain dimension and measure dimension.
getter/setter pairinherited
Methods

noSuchMethod(
Invocation invocation) → dynamic 
Invoked when a nonexistent method or property is accessed.
inherited

toString(
) → String 
A string representation of this object.
inherited
Operators

operator ==(
Object other) → bool 
The equality operator.
override