Rashik

core/basic/avg.go

@@ -0,0 +1,50 @@
+package basic
+
+import (
+	"github.com/n-is/stream-math/utils/cast"
+)
+
+// Avg type
+type Avg struct {
+	avg float64
+}
+
+// InitAvg function
+func InitAvg() *Avg {
+	return &Avg{
+		avg: 0,
+	}
+}
+
+// GetAvg function
+func GetAvg(preAvg float64, v interface{}, n float64) float64 {
+	newAvg := preAvg
+
+	if val, ok := cast.TryFloat(v); ok {
+		newAvg = (preAvg*n + val) / (n + 1)
+	}
+
+	return newAvg
+}
+
+// StreamAvg method
+func (a *Avg) StreamAvg(arr []float64) {
+	a.avg = 0
+
+	for i := 0; i < len(arr); i++ {
+		a.avg = GetAvg(a.avg, arr[i], float64(i))
+	}
+
+}
+
+// func main() {
+// 	fmt.Println("Beginning ... ")
+
+// 	var numberStream = []float64{1000, 2, 3, 17, 50}
+// 	a := InitAvg()
+
+// 	a.StreamAvg(numberStream)
+// 	fmt.Println("Stream Average is :", a.avg)
+
+// 	fmt.Println("End ... ")
+// }

core/basic/avg_test.go

@@ -0,0 +1,56 @@
+package basic
+
+import (
+	"math/rand"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAvg(t *testing.T) {
+
+	t.Run("Natural Numbers Avg", func(t *testing.T) {
+		// Generate data
+		data := make([]float64, 50)
+		for i := 0; i < len(data); i++ {
+			data[i] = float64(i + 1)
+		}
+
+		// Find Calculated Avg
+		sum := float64(0)
+		for i := 0; i < len(data); i++ {
+			sum += data[i]
+		}
+		calculatedAverage := sum / float64(len(data))
+
+		// Find Stream Avg
+		streamAverage := InitAvg()
+		streamAverage.StreamAvg(data)
+
+		// Compare the results
+		assert.Equal(t, calculatedAverage, streamAverage.avg)
+	})
+
+	t.Run("Random Numbers Avg", func(t *testing.T) {
+		// Generate data
+		data := make([]float64, 50)
+		for i := 0; i < len(data); i++ {
+			data[i] = (rand.Float64() - 0.5) * float64(i)
+		}
+
+		// Find Calculated Avg
+		sum := float64(0)
+		for i := 0; i < len(data); i++ {
+			sum += data[i]
+		}
+		calculatedAverage := sum / float64(len(data))
+
+		// Find Stream Avg
+		streamAverage := InitAvg()
+		streamAverage.StreamAvg(data)
+
+		// Compare the results
+		assert.Equal(t, calculatedAverage, streamAverage.avg)
+	})
+
+}