From 432f9df1376561021c821bb24f35439782d1c33b Mon Sep 17 00:00:00 2001
From: c9s <yoanlin93@gmail.com>
Date: Thu, 15 Sep 2022 11:49:19 +0800
Subject: [PATCH] indicator: refactor pivot function to floats

---
 pkg/datatype/floats/pivot.go | 34 ++++++++++++++++++++++++++++++++++
 pkg/indicator/pivotlow.go    | 33 ++-------------------------------
 2 files changed, 36 insertions(+), 31 deletions(-)
 create mode 100644 pkg/datatype/floats/pivot.go

diff --git a/pkg/datatype/floats/pivot.go b/pkg/datatype/floats/pivot.go
new file mode 100644
index 000000000..f79403047
--- /dev/null
+++ b/pkg/datatype/floats/pivot.go
@@ -0,0 +1,34 @@
+package floats
+
+func (s Slice) Pivot(left, right int, f func(a, pivot float64) bool) (float64, bool) {
+	return CalculatePivot(s, left, right, f)
+}
+
+func CalculatePivot(values Slice, left, right int, f func(a, pivot float64) bool) (float64, bool) {
+	length := len(values)
+
+	if right == 0 {
+		right = left
+	}
+
+	if length == 0 || length < left+right+1 {
+		return 0.0, false
+	}
+
+	end := length - 1
+	index := end - right
+	val := values[index]
+
+	for i := index - left; i <= index+right; i++ {
+		if i == index {
+			continue
+		}
+
+		// return if we found lower value
+		if !f(values[i], val) {
+			return 0.0, false
+		}
+	}
+
+	return val, true
+}
diff --git a/pkg/indicator/pivotlow.go b/pkg/indicator/pivotlow.go
index 526b27adf..135b61868 100644
--- a/pkg/indicator/pivotlow.go
+++ b/pkg/indicator/pivotlow.go
@@ -63,43 +63,14 @@ func (inc *PivotLow) PushK(k types.KLine) {
 	inc.EmitUpdate(inc.Last())
 }
 
-func calculatePivotF(values floats.Slice, left, right int, f func(a, pivot float64) bool) (float64, bool) {
-	length := len(values)
-
-	if right == 0 {
-		right = left
-	}
-
-	if length == 0 || length < left+right+1 {
-		return 0.0, false
-	}
-
-	end := length - 1
-	index := end - right
-	val := values[index]
-
-	for i := index - left; i <= index+right; i++ {
-		if i == index {
-			continue
-		}
-
-		// return if we found lower value
-		if !f(values[i], val) {
-			return 0.0, false
-		}
-	}
-
-	return val, true
-}
-
 func calculatePivotHigh(highs floats.Slice, left, right int) (float64, bool) {
-	return calculatePivotF(highs, left, right, func(a, pivot float64) bool {
+	return floats.CalculatePivot(highs, left, right, func(a, pivot float64) bool {
 		return a < pivot
 	})
 }
 
 func calculatePivotLow(lows floats.Slice, left, right int) (float64, bool) {
-	return calculatePivotF(lows, left, right, func(a, pivot float64) bool {
+	return floats.CalculatePivot(lows, left, right, func(a, pivot float64) bool {
 		return a > pivot
 	})
 }