bbgo_origin/pkg/indicator/v2/ewma.go

31 lines
535 B
Go

package indicatorv2
import "github.com/c9s/bbgo/pkg/types"
type EWMAStream struct {
*types.Float64Series
window int
multiplier float64
}
func EWMA2(source types.Float64Source, window int) *EWMAStream {
s := &EWMAStream{
Float64Series: types.NewFloat64Series(),
window: window,
multiplier: 2.0 / float64(1+window),
}
s.Bind(source, s)
return s
}
func (s *EWMAStream) Calculate(v float64) float64 {
last := s.Slice.Last(0)
if last == 0.0 {
return v
}
m := s.multiplier
return (1.0-m)*last + m*v
}