feature: add some new ma indicators

pkg/indicator/dema.go

@@ -0,0 +1,68 @@
+package indicator
+
+import (
+	"github.com/c9s/bbgo/pkg/types"
+)
+
+// Refer: Double Exponential Moving Average
+// Refer URL: https://investopedia.com/terms/d/double-exponential-moving-average.asp
+
+//go:generate callbackgen -type DEMA
+type DEMA struct {
+	types.IntervalWindow
+	Values types.Float64Slice
+	a1     *EWMA
+	a2     *EWMA
+
+	UpdateCallbacks []func(value float64)
+}
+
+func (inc *DEMA) Update(value float64) {
+	if len(inc.Values) == 0 {
+		inc.a1 = &EWMA{IntervalWindow: types.IntervalWindow{inc.Interval, inc.Window}}
+		inc.a2 = &EWMA{IntervalWindow: types.IntervalWindow{inc.Interval, inc.Window}}
+	}
+
+	inc.a1.Update(value)
+	inc.a2.Update(inc.a1.Last())
+	inc.Values.Push(2*inc.a1.Last() - inc.a2.Last())
+	if len(inc.Values) > MaxNumOfEWMA {
+		inc.Values = inc.Values[MaxNumOfEWMATruncateSize-1:]
+	}
+}
+
+func (inc *DEMA) Last() float64 {
+	return inc.Values.Last()
+}
+
+func (inc *DEMA) Index(i int) float64 {
+	if len(inc.Values)-i-1 >= 0 {
+		return inc.Values[len(inc.Values)-1-i]
+	}
+	return 0
+}
+
+func (inc *DEMA) Length() int {
+	return len(inc.Values)
+}
+
+var _ types.Series = &DEMA{}
+
+func (inc *DEMA) calculateAndUpdate(allKLines []types.KLine) {
+	for _, k := range allKLines {
+		inc.Update(k.Close.Float64())
+		inc.EmitUpdate(inc.Last())
+	}
+}
+
+func (inc *DEMA) handleKLineWindowUpdate(interval types.Interval, window types.KLineWindow) {
+	if inc.Interval != interval {
+		return
+	}
+
+	inc.calculateAndUpdate(window)
+}
+
+func (inc *DEMA) Bind(updater KLineWindowUpdater) {
+	updater.OnKLineWindowUpdate(inc.handleKLineWindowUpdate)
+}

pkg/indicator/ewma.go

@@ -124,32 +124,6 @@ func ewma(prices []float64, multiplier float64) float64 {
 	return prices[end]*multiplier + (1-multiplier)*ewma(prices[:end], multiplier)
 }
 
-type KLinePriceMapper func(k types.KLine) float64
-
-func KLineOpenPriceMapper(k types.KLine) float64 {
-	return k.Open.Float64()
-}
-
-func KLineClosePriceMapper(k types.KLine) float64 {
-	return k.Close.Float64()
-}
-
-func KLineTypicalPriceMapper(k types.KLine) float64 {
-	return (k.High.Float64() + k.Low.Float64() + k.Close.Float64()) / 3.
-}
-
-func MapKLinePrice(kLines []types.KLine, f KLinePriceMapper) (prices []float64) {
-	for _, k := range kLines {
-		prices = append(prices, f(k))
-	}
-
-	return prices
-}
-
-type KLineWindowUpdater interface {
-	OnKLineWindowUpdate(func(interval types.Interval, window types.KLineWindow))
-}
-
 func (inc *EWMA) handleKLineWindowUpdate(interval types.Interval, window types.KLineWindow) {
 	if inc.Interval != interval {
 		return

pkg/indicator/hull.go

@@ -0,0 +1,73 @@
+package indicator
+
+import (
+	"math"
+
+	"github.com/c9s/bbgo/pkg/types"
+)
+
+// Refer: Hull Moving Average
+// Refer URL: https://fidelity.com/learning-center/trading-investing/technical-analysis/technical-indicator-guide/hull-moving-average
+//go:generate callbackgen -type HULL
+type HULL struct {
+	types.IntervalWindow
+	ma1 *EWMA
+	ma2 *EWMA
+	result *EWMA
+
+        UpdateCallbacks []func(value float64)
+}
+
+func (inc *HULL) Update(value float64) {
+	if inc.result.Length() == 0 {
+		inc.ma1 = &EWMA{IntervalWindow: types.IntervalWindow{inc.Interval, inc.Window/2}}
+		inc.ma2 = &EWMA{IntervalWindow: types.IntervalWindow{inc.Interval, inc.Window}}
+		inc.result = &EWMA{IntervalWindow: types.IntervalWindow{inc.Interval, int(math.Sqrt(float64(inc.Window)))}}
+	}
+	inc.ma1.Update(value)
+	inc.ma2.Update(value)
+	inc.result.Update(2 * inc.ma1.Last() - inc.ma2.Last())
+}
+
+func (inc *HULL) Last() float64 {
+	return inc.result.Last()
+}
+
+func (inc *HULL) Index(i int) float64 {
+	return inc.result.Index(i)
+}
+
+func (inc *HULL) Length() int {
+	return inc.result.Length()
+}
+
+var _ types.Series = &HULL{}
+
+// TODO: should we just ignore the possible overlapping?
+func (inc *HULL) calculateAndUpdate(allKLines []types.KLine) {
+	doable := false
+	if inc.ma1.Length() == 0 {
+		doable = true
+	}
+        for _, k := range allKLines {
+		if !doable && k.StartTime.After(inc.ma1.LastOpenTime) {
+			doable = true
+		}
+		if doable {
+			inc.Update(k.Close.Float64())
+			inc.EmitUpdate(inc.Last())
+		}
+        }
+}
+
+func (inc *HULL) handleKLineWindowUpdate(interval types.Interval, window types.KLineWindow) {
+        if inc.Interval != interval {
+                return
+        }
+
+        inc.calculateAndUpdate(window)
+}
+
+func (inc *HULL) Bind(updater KLineWindowUpdater) {
+        updater.OnKLineWindowUpdate(inc.handleKLineWindowUpdate)
+}

pkg/indicator/line.go

@@ -37,11 +37,11 @@ func (l *Line) Bind(updater KLineWindowUpdater) {
 }
 
 func (l *Line) Last() float64 {
-	return (l.end-l.start) / float64(l.startIndex - l.endIndex) * float64(l.endIndex) + l.end
+	return (l.end-l.start)/float64(l.startIndex-l.endIndex)*float64(l.endIndex) + l.end
 }
 
 func (l *Line) Index(i int) float64 {
-	return (l.end-l.start) / float64(l.startIndex - l.endIndex) * float64(l.endIndex - i) + l.end
+	return (l.end-l.start)/float64(l.startIndex-l.endIndex)*float64(l.endIndex-i) + l.end
 }
 
 func (l *Line) Length() int {

pkg/indicator/tema.go

@@ -0,0 +1,73 @@
+package indicator
+
+import (
+	"github.com/c9s/bbgo/pkg/types"
+)
+
+// Refer: Triple Exponential Moving Average (TEMA)
+// URL: https://investopedia.com/terms/t/triple-exponential-moving-average.asp
+
+//go:generate callbackgen -type TEMA
+type TEMA struct {
+	types.IntervalWindow
+	Values types.Float64Slice
+	A1     *EWMA
+	A2     *EWMA
+	A3     *EWMA
+
+	UpdateCallbacks []func(value float64)
+}
+
+func (inc *TEMA) Update(value float64) {
+	if len(inc.Values) == 0 {
+		inc.A1 = &EWMA{IntervalWindow: types.IntervalWindow{inc.Interval, inc.Window}}
+		inc.A2 = &EWMA{IntervalWindow: types.IntervalWindow{inc.Interval, inc.Window}}
+		inc.A3 = &EWMA{IntervalWindow: types.IntervalWindow{inc.Interval, inc.Window}}
+	}
+	inc.A1.Update(value)
+	a1 := inc.A1.Last()
+	inc.A2.Update(a1)
+	a2 := inc.A2.Last()
+	inc.A3.Update(a2)
+	a3 := inc.A3.Last()
+	inc.Values.Push(3*a1 - 3*a2 + a3)
+}
+
+func (inc *TEMA) Last() float64 {
+	if len(inc.Values) > 0 {
+		return inc.Values[len(inc.Values)-1]
+	}
+	return 0.0
+}
+
+func (inc *TEMA) Index(i int) float64 {
+	if i >= len(inc.Values) {
+		return 0
+	}
+	return inc.Values[len(inc.Values)-i-1]
+}
+
+func (inc *TEMA) Length() int {
+	return len(inc.Values)
+}
+
+var _ types.Series = &TEMA{}
+
+func (inc *TEMA) calculateAndUpdate(allKLines []types.KLine) {
+	for _, k := range allKLines {
+		inc.Update(k.Close.Float64())
+		inc.EmitUpdate(inc.Last())
+	}
+}
+
+func (inc *TEMA) handleKLineWindowUpdate(interval types.Interval, window types.KLineWindow) {
+	if inc.Interval != interval {
+		return
+	}
+
+	inc.calculateAndUpdate(window)
+}
+
+func (inc *TEMA) Bind(updater KLineWindowUpdater) {
+	updater.OnKLineWindowUpdate(inc.handleKLineWindowUpdate)
+}

pkg/indicator/till.go

@@ -0,0 +1 @@
+package indicator

pkg/indicator/tsf.go

@@ -0,0 +1 @@
+package indicator

pkg/indicator/util.go

@@ -0,0 +1,29 @@
+package indicator
+
+import "github.com/c9s/bbgo/pkg/types"
+
+type KLinePriceMapper func(k types.KLine) float64
+
+func KLineOpenPriceMapper(k types.KLine) float64 {
+	return k.Open.Float64()
+}
+
+func KLineClosePriceMapper(k types.KLine) float64 {
+	return k.Close.Float64()
+}
+
+func KLineTypicalPriceMapper(k types.KLine) float64 {
+	return (k.High.Float64() + k.Low.Float64() + k.Close.Float64()) / 3.
+}
+
+func MapKLinePrice(kLines []types.KLine, f KLinePriceMapper) (prices []float64) {
+	for _, k := range kLines {
+		prices = append(prices, f(k))
+	}
+
+	return prices
+}
+
+type KLineWindowUpdater interface {
+	OnKLineWindowUpdate(func(interval types.Interval, window types.KLineWindow))
+}

pkg/indicator/vidya.go

@@ -0,0 +1 @@
+package indicator