Add ad indicator

pkg/indicator/ad.go

@@ -0,0 +1,66 @@
+package indicator
+
+import (
+	"time"
+
+	"github.com/c9s/bbgo/pkg/types"
+)
+
+/*
+ad implements accumulation/distribution indicator
+
+Accumulation/Distribution Indicator (A/D)
+- https://www.investopedia.com/terms/a/accumulationdistribution.asp
+*/
+//go:generate callbackgen -type AD
+type AD struct {
+	types.IntervalWindow
+	Values   Float64Slice
+	PrePrice float64
+
+	EndTime         time.Time
+	UpdateCallbacks []func(value float64)
+}
+
+func (inc *AD) update(kLine types.KLine) {
+	close := kLine.Close
+	high := kLine.High
+	low := kLine.Low
+	volume := kLine.Volume
+
+	moneyFlowVolume := ((2*close - high - low) / (high - low)) * volume
+
+	ad := inc.Last() + moneyFlowVolume
+	inc.Values.Push(ad)
+}
+
+func (inc *AD) Last() float64 {
+	if len(inc.Values) == 0 {
+		return 0.0
+	}
+	return inc.Values[len(inc.Values)-1]
+}
+
+func (inc *AD) calculateAndUpdate(kLines []types.KLine) {
+	for i, k := range kLines {
+		if inc.EndTime != zeroTime && k.EndTime.Before(inc.EndTime) {
+			continue
+		}
+
+		inc.update(k)
+		inc.EmitUpdate(inc.Last())
+		inc.EndTime = kLines[i].EndTime
+	}
+
+}
+func (inc *AD) handleKLineWindowUpdate(interval types.Interval, window types.KLineWindow) {
+	if inc.Interval != interval {
+		return
+	}
+
+	inc.calculateAndUpdate(window)
+}
+
+func (inc *AD) Bind(updater KLineWindowUpdater) {
+	updater.OnKLineWindowUpdate(inc.handleKLineWindowUpdate)
+}

pkg/indicator/ad_callbacks.go

@@ -0,0 +1,15 @@
+// Code generated by "callbackgen -type AD"; DO NOT EDIT.
+
+package indicator
+
+import ()
+
+func (inc *AD) OnUpdate(cb func(value float64)) {
+	inc.UpdateCallbacks = append(inc.UpdateCallbacks, cb)
+}
+
+func (inc *AD) EmitUpdate(value float64) {
+	for _, cb := range inc.UpdateCallbacks {
+		cb(value)
+	}
+}