bbgo_origin/pkg/indicator/sma.go

113 lines
2.3 KiB
Go

package indicator
import (
"fmt"
"time"
"github.com/c9s/bbgo/pkg/types"
)
const MaxNumOfSMA = 5_000
const MaxNumOfSMATruncateSize = 100
//go:generate callbackgen -type SMA
type SMA struct {
types.SeriesBase
types.IntervalWindow
Values types.Float64Slice
Cache *types.Queue
EndTime time.Time
UpdateCallbacks []func(value float64)
}
func (inc *SMA) Last() float64 {
if inc.Values.Length() == 0 {
return 0.0
}
return inc.Values.Last()
}
func (inc *SMA) Index(i int) float64 {
if i >= inc.Values.Length() {
return 0.0
}
return inc.Values.Index(i)
}
func (inc *SMA) Length() int {
return inc.Values.Length()
}
var _ types.SeriesExtend = &SMA{}
func (inc *SMA) Update(value float64) {
if inc.Cache == nil {
inc.Cache = types.NewQueue(inc.Window)
inc.SeriesBase.Series = inc
}
inc.Cache.Update(value)
if inc.Cache.Length() < inc.Window {
return
}
inc.Values.Push(types.Mean(inc.Cache))
if inc.Values.Length() > MaxNumOfSMA {
inc.Values = inc.Values[MaxNumOfSMATruncateSize-1:]
}
}
func (inc *SMA) PushK(k types.KLine) {
inc.Update(k.Close.Float64())
}
func (inc *SMA) CalculateAndUpdate(kLines []types.KLine) {
var index = len(kLines) - 1
var kline = kLines[index]
if inc.EndTime != zeroTime && kline.EndTime.Before(inc.EndTime) {
return
}
if inc.Cache == nil {
for _, k := range kLines {
inc.PushK(k)
inc.EndTime = k.EndTime.Time()
inc.EmitUpdate(inc.Values.Last())
}
} else {
inc.PushK(kline)
inc.EndTime = kline.EndTime.Time()
inc.EmitUpdate(inc.Values.Last())
}
}
func (inc *SMA) handleKLineWindowUpdate(interval types.Interval, window types.KLineWindow) {
if inc.Interval != interval {
return
}
inc.CalculateAndUpdate(window)
}
func (inc *SMA) Bind(updater KLineWindowUpdater) {
updater.OnKLineWindowUpdate(inc.handleKLineWindowUpdate)
}
func calculateSMA(kLines []types.KLine, window int, priceF KLinePriceMapper) (float64, error) {
length := len(kLines)
if length == 0 || length < window {
return 0.0, fmt.Errorf("insufficient elements for calculating SMA with window = %d", window)
}
if length != window {
return 0.0, fmt.Errorf("too much klines passed in, requires only %d klines", window)
}
sum := 0.0
for _, k := range kLines {
sum += priceF(k)
}
avg := sum / float64(window)
return avg, nil
}