package indicator import ( "time" "github.com/c9s/bbgo/pkg/datatype/floats" "github.com/c9s/bbgo/pkg/types" ) /* vwma implements the volume weighted moving average (VWMA) indicator: Calculation: pv = element-wise multiplication of close prices and volumes VWMA = SMA(pv, window) / SMA(volumes, window) Volume Weighted Moving Average - https://www.motivewave.com/studies/volume_weighted_moving_average.htm */ //go:generate callbackgen -type VWMA type VWMA struct { types.SeriesBase types.IntervalWindow Values floats.Slice PriceVolumeSMA *SMA VolumeSMA *SMA EndTime time.Time updateCallbacks []func(value float64) } func (inc *VWMA) Last() float64 { if len(inc.Values) == 0 { return 0.0 } return inc.Values[len(inc.Values)-1] } func (inc *VWMA) 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 *VWMA) Length() int { return len(inc.Values) } var _ types.SeriesExtend = &VWMA{} func (inc *VWMA) Update(price, volume float64) { if inc.PriceVolumeSMA == nil { inc.PriceVolumeSMA = &SMA{IntervalWindow: inc.IntervalWindow} inc.SeriesBase.Series = inc } if inc.VolumeSMA == nil { inc.VolumeSMA = &SMA{IntervalWindow: inc.IntervalWindow} } inc.PriceVolumeSMA.Update(price * volume) inc.VolumeSMA.Update(volume) pv := inc.PriceVolumeSMA.Last() v := inc.VolumeSMA.Last() vwma := pv / v inc.Values.Push(vwma) } func (inc *VWMA) PushK(k types.KLine) { if inc.EndTime != zeroTime && k.EndTime.Before(inc.EndTime) { return } inc.Update(k.Close.Float64(), k.Volume.Float64()) } func (inc *VWMA) CalculateAndUpdate(allKLines []types.KLine) { if len(allKLines) < inc.Window { return } var last = allKLines[len(allKLines)-1] if inc.VolumeSMA == nil { for _, k := range allKLines { if inc.EndTime != zeroTime && k.EndTime.Before(inc.EndTime) { return } inc.Update(k.Close.Float64(), k.Volume.Float64()) } } else { inc.Update(last.Close.Float64(), last.Volume.Float64()) } inc.EndTime = last.EndTime.Time() inc.EmitUpdate(inc.Values.Last()) } func (inc *VWMA) handleKLineWindowUpdate(interval types.Interval, window types.KLineWindow) { if inc.Interval != interval { return } inc.CalculateAndUpdate(window) } func (inc *VWMA) Bind(updater KLineWindowUpdater) { updater.OnKLineWindowUpdate(inc.handleKLineWindowUpdate) }