WmaIndicator<T, D> class

Renders weighted moving average (WMA) indicator.

A weighted moving average (WMA) is an arithmetic moving average calculated by adding recent closing prices and then dividing the total by the number of time periods in the calculation average.

It also has a valueField property. Based on this property, the indicator will be rendered.

The indicator elements are:

  • The dataSource, which is used provide data for the technical indicators without any series.
  • The xValueMapper, which is a value mapper to map the x values with the technical indicator.
  • The highValueMapper, which is a value mapper to map the high values with the technical indicator.
  • The lowValueMapper, which is a value mapper to map the low values with the technical indicator.
  • The openValueMapper, which is a value mapper to map the open values with the technical indicator.
  • The closeValueMapper, which is a value mapper to map the close values with the technical indicator.
  • The xAxisName and yAxisName, which is used map the technical indicator with the multiple axes.
  • The seriesName, which is used map the technical indicator with the series based on names.
  • The valueField, which is used to determines the field for the rendering of WMA indicator.
  • The period, which is used determines the start point for the rendering of technical indicator.

Formula

Data (Closing Prices for Each Day):

  • Day 1: $100
  • Day 2: $105
  • Day 3: $110
  • Day 4: $120
  • Day 5: $103
  • ...
  • Day 15: $110
  • Day 16: $108
  • …
  • Day 29: $110
  • Day 30: $120

Calculation of WMA:

  • WMA for single data = currentPrice * (n/ sum of period);

  • The equation we use for weighing each number is the day number divided by the sum of all day numbers. Since we are looking at five days, the sum of all day numbers in this example is 15 (i.e., 5 + 4 + 3 + 2 + 1).

  • WMA on Period 3:

  • If we need to calculate the 3rd day WMA means, current value is 110, period 3 days sum is 6 (3+2+1), then

  • 100 * (1/6) = 6.25

  • 105 * (2/6) = 17.5

  • 110 * (3/6) = 18.33

  • WMA on Period 16:

  • If we need to calculate the 16th day WMA means, current value is 108, previous 16-day sum is 136 (16+15+14+13+...+1).

  • Day1: 100 * (1/136) = 0.7

  • ....

  • Day 16: 108 * (16/136) = 12.070

Example

This snippet shows how to create a WmaIndicator by mapping the series data source.


 @override
 Widget build(BuildContext context) {
   return MaterialApp(
     home: Scaffold(
       body: Center(
         child: SfCartesianChart(
           primaryXAxis: const DateTimeAxis(),
           primaryYAxis: const NumericAxis(),
           axes: const <ChartAxis>[
             NumericAxis(
               majorGridLines: MajorGridLines(width: 0),
               opposedPosition: true,
               name: 'yAxis',
             ),
           ],
           indicators: <TechnicalIndicator<ChartSampleData, DateTime>>[
             WmaIndicator<ChartSampleData, DateTime>(
               seriesName: 'AAPL',
               yAxisName: 'yAxis',
               period: 15,
             ),
           ],
           series: <CartesianSeries<ChartSampleData, DateTime>>[
             HiloOpenCloseSeries<ChartSampleData, DateTime>(
               dataSource: getChartData(),
               xValueMapper: (ChartSampleData sales, _) => sales.x as DateTime,
               lowValueMapper: (ChartSampleData sales, _) => sales.low,
               highValueMapper: (ChartSampleData sales, _) => sales.high,
               openValueMapper: (ChartSampleData sales, _) => sales.open,
               closeValueMapper: (ChartSampleData sales, _) => sales.close,
               name: 'AAPL',
             ),
           ],
         ),
       ),
     ),
   );
 }

This snippet shows how to create a WmaIndicator using a direct data source.


 @override
 Widget build(BuildContext context) {
   return MaterialApp(
     home: Scaffold(
       body: Center(
         child: SfCartesianChart(
           primaryXAxis: const DateTimeAxis(),
           primaryYAxis: const NumericAxis(),
           axes: const <ChartAxis>[
             NumericAxis(
               majorGridLines: MajorGridLines(width: 0),
               opposedPosition: true,
               name: 'yAxis',
             ),
           ],
           indicators: <TechnicalIndicator<ChartSampleData, DateTime>>[
             WmaIndicator<ChartSampleData, DateTime>(
               dataSource: getChartData(),
               xValueMapper: (ChartSampleData sales, _) => sales.x as DateTime,
               lowValueMapper: (ChartSampleData sales, _) => sales.low,
               highValueMapper: (ChartSampleData sales, _) => sales.high,
               openValueMapper: (ChartSampleData sales, _) => sales.open,
               closeValueMapper: (ChartSampleData sales, _) => sales.close,
               yAxisName: 'yAxis',
               period: 15,
             ),
           ],
         ),
       ),
     ),
   );
 }
Inheritance
Annotations

Constructors

WmaIndicator({bool isVisible = true, String? xAxisName, String? yAxisName, String? seriesName, List<double> dashArray = const <double>[0, 0], double animationDuration = 1500, double animationDelay = 0, List<T>? dataSource, ChartValueMapper<T, D>? xValueMapper, ChartValueMapper<T, num>? highValueMapper, ChartValueMapper<T, num>? lowValueMapper, ChartValueMapper<T, num>? openValueMapper, ChartValueMapper<T, num>? closeValueMapper, String? name, bool isVisibleInLegend = true, LegendIconType legendIconType = LegendIconType.seriesType, String? legendItemText, Color signalLineColor = Colors.blue, double signalLineWidth = 2, int period = 14, String valueField = 'close', ChartIndicatorRenderCallback? onRenderDetailsUpdate})
Creating an argument constructor of WmaIndicator class.

Properties

animationDelay → double
Delay duration of the technical indicator's animation. It takes a millisecond value as input. By default, the technical indicator will get animated for the specified duration. If animationDelay is specified, then the technical indicator will begin to animate after the specified duration.
finalinherited
animationDuration → double
Animation duration for the technical indicators.
finalinherited
closeValueMapper → ChartIndexedValueMapper<num?>?
Value mapper to map the close values with technical indicators.
finalinherited
dashArray → List<double>
Property to provide dash array for the technical indicators.
finalinherited
dataSource → List<T>?
Property to provide data for the technical indicators without any series.
finalinherited
hashCode → int
The hash code for this object.
no setteroverride
highValueMapper → ChartIndexedValueMapper<num?>?
Value mapper to map the high values with technical indicators.
finalinherited
isVisible → bool
Boolean property to change the visibility of the technical indicators.
finalinherited
isVisibleInLegend → bool
Boolean property to determine the rendering of legends for the technical indicators.
finalinherited
legendIconType → LegendIconType
Property to provide icon type for the technical indicators legend.
finalinherited
legendItemText → String?
Property to provide the text for the technical indicators legend.
finalinherited
lowValueMapper → ChartIndexedValueMapper<num?>?
Value mapper to map the low values with technical indicators.
finalinherited
name → String?
Property to provide name for the technical indicators.
finalinherited
onRenderDetailsUpdate → ChartIndicatorRenderCallback?
Callback which gets called while rendering the indicators.
finalinherited
openValueMapper → ChartIndexedValueMapper<num?>?
Value mapper to map the open values with technical indicators.
finalinherited
period → int
Period determines the start point for the rendering of technical indicators.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
seriesName → String?
Property to link indicators to a series based on names.
finalinherited
signalLineColor → Color
Property to provide the color of the signal line in the technical indicators.
finalinherited
signalLineWidth → double
Property to provide the width of the signal line in the technical indicators.
finalinherited
valueField → String
Value field value for WMA indicator.
final
volumeValueMapper → ChartIndexedValueMapper<num?>?
Volume of series.
finalinherited
xAxisName → String?
Property to map the technical indicators with the axes.
finalinherited
xValueMapper → ChartIndexedValueMapper<D>?
Value mapper to map the x values with technical indicators.
finalinherited
yAxisName → String?
Property to map the technical indicators with the axes.
finalinherited

Methods

noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
override

Operators

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