package fmaker import ( "fmt" "time" "github.com/c9s/bbgo/pkg/datatype/floats" "github.com/c9s/bbgo/pkg/indicator" "github.com/c9s/bbgo/pkg/types" ) //go:generate callbackgen -type S7 type S7 struct { types.IntervalWindow // Values Values floats.Slice EndTime time.Time UpdateCallbacks []func(val float64) } func (inc *S7) Last(int) float64 { if len(inc.Values) == 0 { return 0.0 } return inc.Values[len(inc.Values)-1] } func (inc *S7) CalculateAndUpdate(klines []types.KLine) { if len(klines) < inc.Window { return } var end = len(klines) - 1 var lastKLine = klines[end] if inc.EndTime != zeroTime && lastKLine.GetEndTime().Before(inc.EndTime) { return } var recentT = klines[end-(inc.Window-1) : end+1] val, err := calculateS7(recentT, types.KLineOpenPriceMapper, types.KLineClosePriceMapper) if err != nil { log.WithError(err).Error("can not calculate") return } inc.Values.Push(val) if len(inc.Values) > indicator.MaxNumOfVOL { inc.Values = inc.Values[indicator.MaxNumOfVOLTruncateSize-1:] } inc.EndTime = klines[end].GetEndTime().Time() inc.EmitUpdate(val) } func (inc *S7) handleKLineWindowUpdate(interval types.Interval, window types.KLineWindow) { if inc.Interval != interval { return } inc.CalculateAndUpdate(window) } func (inc *S7) Bind(updater indicator.KLineWindowUpdater) { updater.OnKLineWindowUpdate(inc.handleKLineWindowUpdate) } func calculateS7(klines []types.KLine, valOpen KLineValueMapper, valClose KLineValueMapper) (float64, error) { window := 2 length := len(klines) if length == 0 || length < window { return 0., fmt.Errorf("insufficient elements for calculating with window = %d", window) } var opens floats.Slice var closes floats.Slice for _, k := range klines { opens.Push(valOpen(k)) closes.Push(valClose(k)) } O := opens.Last(0) C := closes.Last(0) alpha := -(1 - O/C) return alpha, nil }