Range回傳改float64

datalist.go

@@ -85,7 +85,7 @@ type IDataList interface {
 	StdevP() float64
 	Var() float64
 	VarP() float64
-	Range() interface{}
+	Range() float64
 	Quartile(int) interface{}
 	IQR() interface{}
 	Percentile(float64) interface{}
@@ -1508,17 +1508,20 @@ func (dl *DataList) VarP() float64 {
 }
 
 // Range calculates the range of the DataList.
-// Returns the range.
-// Returns nil if the DataList is empty.
-// Range returns the range of the DataList.
-func (dl *DataList) Range() interface{} {
+// Returns math.NaN() if the DataList is empty or if Max or Min cannot be calculated.
+func (dl *DataList) Range() float64 {
 	if len(dl.data) == 0 {
-		LogWarning("DataList.Range(): DataList is empty, returning nil.")
-		return nil
+		LogWarning("DataList.Range(): DataList is empty.")
+		return math.NaN()
 	}
 
-	max := ToFloat64(dl.Max())
-	min := ToFloat64(dl.Min())
+	max := dl.Max()
+	min := dl.Min()
+
+	if math.IsNaN(max) || math.IsNaN(min) {
+		LogWarning("DataList.Range(): Max or Min calculation failed.")
+		return math.NaN()
+	}
 
 	return max - min
 }

insyra_test.go

@@ -268,6 +268,16 @@ func TestVarP(t *testing.T) {
 	}
 }
 
+// 測試 Range 函數
+func TestRange(t *testing.T) {
+	dl := NewDataList(1, 2, 3, 4)
+	r := dl.Range()
+
+	if !float64Equal(r, 3) {
+		t.Errorf("Expected range 3, got %v", r)
+	}
+}
+
 // 測試 SetName 和 GetName 函數
 func TestSetName(t *testing.T) {
 	dl := NewDataList(1, 2, 3, 4)