bbgo/pkg/strategy/factorzoo/factors/price_mean_reversion.go

103 lines
2.2 KiB
Go

package factorzoo
import (
"time"
"gonum.org/v1/gonum/stat"
"git.qtrade.icu/lychiyu/bbgo/pkg/datatype/floats"
"git.qtrade.icu/lychiyu/bbgo/pkg/indicator"
"git.qtrade.icu/lychiyu/bbgo/pkg/types"
)
// price mean reversion
// assume that the quotient of SMA over close price will dynamically revert into one.
// so this fraction value is our alpha, PMR
//go:generate callbackgen -type PMR
type PMR struct {
types.IntervalWindow
types.SeriesBase
Values floats.Slice
SMA *indicator.SMA
EndTime time.Time
updateCallbacks []func(value float64)
}
var _ types.SeriesExtend = &PMR{}
func (inc *PMR) Update(price float64) {
if inc.SeriesBase.Series == nil {
inc.SeriesBase.Series = inc
inc.SMA = &indicator.SMA{IntervalWindow: inc.IntervalWindow}
}
inc.SMA.Update(price)
if inc.SMA.Length() >= inc.Window {
reversion := inc.SMA.Last(0) / price
inc.Values.Push(reversion)
}
}
func (inc *PMR) Last(i int) float64 {
return inc.Values.Last(i)
}
func (inc *PMR) Index(i int) float64 {
return inc.Last(i)
}
func (inc *PMR) Length() int {
return len(inc.Values)
}
func (inc *PMR) CalculateAndUpdate(allKLines []types.KLine) {
if len(inc.Values) == 0 {
for _, k := range allKLines {
inc.PushK(k)
}
inc.EmitUpdate(inc.Last(0))
} else {
k := allKLines[len(allKLines)-1]
inc.PushK(k)
inc.EmitUpdate(inc.Last(0))
}
}
func (inc *PMR) handleKLineWindowUpdate(interval types.Interval, window types.KLineWindow) {
if inc.Interval != interval {
return
}
inc.CalculateAndUpdate(window)
}
func (inc *PMR) Bind(updater indicator.KLineWindowUpdater) {
updater.OnKLineWindowUpdate(inc.handleKLineWindowUpdate)
}
func (inc *PMR) PushK(k types.KLine) {
if inc.EndTime != zeroTime && k.EndTime.Before(inc.EndTime) {
return
}
inc.Update(types.KLineClosePriceMapper(k))
inc.EndTime = k.EndTime.Time()
inc.EmitUpdate(inc.Last(0))
}
func CalculateKLinesPMR(allKLines []types.KLine, window int) float64 {
return pmr(types.MapKLinePrice(allKLines, types.KLineClosePriceMapper), window)
}
func pmr(prices []float64, window int) float64 {
var end = len(prices) - 1
if end == 0 {
return prices[0]
}
reversion := -stat.Mean(prices[end-window:end], nil) / prices[end]
return reversion
}