diff --git a/macd_series.go b/macd_series.go
index 85a0813..4ce7bc9 100644
--- a/macd_series.go
+++ b/macd_series.go
@@ -233,17 +233,6 @@ func (macdl MACDLineSeries) Len() int {
 	return macdl.InnerSeries.Len()
 }
 
-// GetSigma returns the smoothing factor for the serise.
-func (macdl MACDLineSeries) GetSigma(defaults ...float64) float64 {
-	if macdl.Sigma == 0 {
-		if len(defaults) > 0 {
-			return defaults[0]
-		}
-		return DefaultEMASigma
-	}
-	return macdl.Sigma
-}
-
 // GetValue gets a value at a given index. For MACD it is the signal value.
 func (macdl MACDLineSeries) GetValue(index int) (x float64, y float64) {
 	if macdl.InnerSeries == nil {