Add standard deviation in utils

Signed-off-by: Qifan Deng <[email protected]>

Author: pancak3

pkg/common/utils.go

@@ -261,3 +261,22 @@ func init() {
 func Tokenize(text string) []string {
 	return re.FindAllString(text, -1)
 }
+
+// Calculate standard deviation of an int array
+func StdDevInt(data []int) float64 {
+	var sum int
+	for _, value := range data {
+		sum += value
+	}
+	mean := sum / len(data)
+
+	var sumSquares int
+	for _, value := range data {
+		diff := value - mean
+		sumSquares += diff * diff
+	}
+
+	variance := sumSquares / len(data)
+
+	return math.Sqrt(float64(variance))
+}

pkg/common/utils_test.go

@@ -156,4 +156,16 @@ var _ = Describe("Utils", Ordered, func() {
 		}
 	})
 
+	Context("Standard Deviation", func() {
+		It("should return 0 for a single element", func() {
+			data := []int{42}
+			Expect(StdDevInt(data)).To(Equal(0.0))
+		})
+
+		It("should return the correct standard deviation for multiple elements", func() {
+			data := []int{1, 2, 3, 4, 5}
+			Expect(StdDevInt(data)).To(Equal(1.4142135623730951))
+		})
+	})
+
 })