bbgo_origin/pkg/indicator/vwap.go

111 lines
2.4 KiB
Go

package indicator
import (
"time"
"github.com/c9s/bbgo/pkg/datatype/floats"
"github.com/c9s/bbgo/pkg/types"
)
/*
vwap implements the volume weighted average price (VWAP) indicator:
Volume Weighted Average Price (VWAP) Definition
- https://www.investopedia.com/terms/v/vwap.asp
Volume-Weighted Average Price (VWAP) Explained
- https://academy.binance.com/en/articles/volume-weighted-average-price-vwap-explained
*/
//go:generate callbackgen -type VWAP
type VWAP struct {
types.SeriesBase
types.IntervalWindow
Values floats.Slice
Prices floats.Slice
Volumes floats.Slice
WeightedSum float64
VolumeSum float64
EndTime time.Time
UpdateCallbacks []func(value float64)
}
func (inc *VWAP) Update(price, volume float64) {
if len(inc.Prices) == 0 {
inc.SeriesBase.Series = inc
}
inc.Prices.Push(price)
inc.Volumes.Push(volume)
if inc.Window != 0 && len(inc.Prices) > inc.Window {
popIndex := len(inc.Prices) - inc.Window - 1
inc.WeightedSum -= inc.Prices[popIndex] * inc.Volumes[popIndex]
inc.VolumeSum -= inc.Volumes[popIndex]
}
inc.WeightedSum += price * volume
inc.VolumeSum += volume
vwap := inc.WeightedSum / inc.VolumeSum
inc.Values.Push(vwap)
}
func (inc *VWAP) Last() float64 {
if len(inc.Values) == 0 {
return 0.0
}
return inc.Values[len(inc.Values)-1]
}
func (inc *VWAP) Index(i int) float64 {
length := len(inc.Values)
if length == 0 || length-i-1 < 0 {
return 0
}
return inc.Values[length-i-1]
}
func (inc *VWAP) Length() int {
return len(inc.Values)
}
var _ types.SeriesExtend = &VWAP{}
func (inc *VWAP) PushK(k types.KLine) {
inc.Update(KLineTypicalPriceMapper(k), k.Volume.Float64())
}
func (inc *VWAP) CalculateAndUpdate(allKLines []types.KLine) {
for _, k := range allKLines {
if inc.EndTime != zeroTime && !k.EndTime.After(inc.EndTime) {
continue
}
inc.PushK(k)
}
inc.EmitUpdate(inc.Last())
inc.EndTime = allKLines[len(allKLines)-1].EndTime.Time()
}
func (inc *VWAP) handleKLineWindowUpdate(interval types.Interval, window types.KLineWindow) {
if inc.Interval != interval {
return
}
inc.CalculateAndUpdate(window)
}
func (inc *VWAP) Bind(updater KLineWindowUpdater) {
updater.OnKLineWindowUpdate(inc.handleKLineWindowUpdate)
}
func calculateVWAP(klines []types.KLine, priceF KLineValueMapper, window int) float64 {
vwap := VWAP{IntervalWindow: types.IntervalWindow{Window: window}}
for _, k := range klines {
vwap.Update(priceF(k), k.Volume.Float64())
}
return vwap.Last()
}