cec2020: generalise Hybrid1 func's internals

bench/cec2020/benchFunctions.go

@@ -107,35 +107,25 @@ func Hybrid1(x []float64) float64 {
 	nx := len(x)
 	fnx := float64(nx)
 
-	f1 := SchwefelModified
-	f2 := Rastrigin
-	f3 := HighConditionedElliptic
-
-	// percentages.
-	p := []float64{0.3, 0.3, 0.4}
-	gnx := make([]float64, len(p))
-	gnxsum := 0.0
-
-	for i := 0; i < len(p)-1; i++ {
-		gnx[i] = math.Ceil(p[i] * fnx)
-		gnxsum += gnx[i]
+	funcs := []func([]float64) float64{
+		SchwefelModified,
+		Rastrigin,
+		HighConditionedElliptic,
 	}
-
-	gnx[len(p)] = fnx - gnxsum
+	// percentages used to control the amount of contribution of each func.
+	p := []float64{0.3, 0.3, 0.4}
+	gnx := getGnx(p, fnx)
 
 	z := newOpt(nx)
-	mz := make([]float64, nx)
+	mz := getMz(x, z)
 
-	for i := range x {
-		mz = append(mz, x[i]*z[i])
+	var sum float64
+
+	for i := range funcs {
+		sum += funcs[i](mz) * gnx[i]
 	}
 
-	// results.
-	r1 := f1(mz)
-	r2 := f2(mz)
-	r3 := f3(mz)
-
-	return gnx[0]*r1 + gnx[1]*r2 + gnx[2]*r3
+	return sum
 }
 
 // Hybrid2 is the "Hybrid Function 2" of CEC2020.

bench/cec2020/helperFunctions.go

@@ -164,3 +164,30 @@ func newOpt(n int) []float64 {
 
 	return xopt
 }
+
+// getGnx calculates G_nx.
+func getGnx(p []float64, fnx float64) []float64 {
+	gnx := make([]float64, len(p))
+	gnxsum := 0.0
+
+	for i := 0; i < len(p)-1; i++ {
+		gnx[i] = math.Ceil(p[i] * fnx)
+		gnxsum += gnx[i]
+	}
+
+	gnx[len(p)] = fnx - gnxsum
+
+	return gnx
+}
+
+// getMz calculates Mz.
+func getMz(x []float64, z []float64) []float64 {
+	nx := len(x)
+	mz := make([]float64, nx)
+
+	for i := range x {
+		mz = append(mz, x[i]*z[i])
+	}
+
+	return mz
+}