bbgo_origin/pkg/strategy/supertrend/linreg.go
2023-06-01 07:46:50 +08:00

100 lines
2.3 KiB
Go

package supertrend
import (
"time"
"github.com/c9s/bbgo/pkg/datatype/floats"
"github.com/c9s/bbgo/pkg/indicator"
"github.com/c9s/bbgo/pkg/types"
)
// LinReg is Linear Regression baseline
type LinReg struct {
types.SeriesBase
types.IntervalWindow
// Values are the slopes of linear regression baseline
Values floats.Slice
klines types.KLineWindow
EndTime time.Time
}
// Last slope of linear regression baseline
func (lr *LinReg) Last(i int) float64 {
return lr.Values.Last(i)
}
// Index returns the slope of specified index
func (lr *LinReg) Index(i int) float64 {
return lr.Last(i)
}
// Length of the slope values
func (lr *LinReg) Length() int {
return lr.Values.Length()
}
var _ types.SeriesExtend = &LinReg{}
// Update Linear Regression baseline slope
func (lr *LinReg) Update(kline types.KLine) {
lr.klines.Add(kline)
lr.klines.Truncate(lr.Window)
if len(lr.klines) < lr.Window {
lr.Values.Push(0)
return
}
var sumX, sumY, sumXSqr, sumXY float64 = 0, 0, 0, 0
end := len(lr.klines) - 1 // The last kline
for i := end; i >= end-lr.Window+1; i-- {
val := lr.klines[i].GetClose().Float64()
per := float64(end - i + 1)
sumX += per
sumY += val
sumXSqr += per * per
sumXY += val * per
}
length := float64(lr.Window)
slope := (length*sumXY - sumX*sumY) / (length*sumXSqr - sumX*sumX)
average := sumY / length
endPrice := average - slope*sumX/length + slope
startPrice := endPrice + slope*(length-1)
lr.Values.Push((endPrice - startPrice) / (length - 1))
log.Debugf("linear regression baseline slope: %f", lr.Last(0))
}
func (lr *LinReg) BindK(target indicator.KLineClosedEmitter, symbol string, interval types.Interval) {
target.OnKLineClosed(types.KLineWith(symbol, interval, lr.PushK))
}
func (lr *LinReg) PushK(k types.KLine) {
var zeroTime = time.Time{}
if lr.EndTime != zeroTime && k.EndTime.Before(lr.EndTime) {
return
}
lr.Update(k)
lr.EndTime = k.EndTime.Time()
}
func (lr *LinReg) LoadK(allKLines []types.KLine) {
for _, k := range allKLines {
lr.PushK(k)
}
}
// GetSignal get linear regression signal
func (lr *LinReg) GetSignal() types.Direction {
var lrSignal types.Direction = types.DirectionNone
switch {
case lr.Last(0) > 0:
lrSignal = types.DirectionUp
case lr.Last(0) < 0:
lrSignal = types.DirectionDown
}
return lrSignal
}