func Sum(x []float64) float64 {
	var sum float64
	for _, v := range x {
		sum += v
	}
	return sum
}
Sum is
var sum float64
for i := range x {
sum += x[i]
}
package f64
import "math"
func L1Norm(x []float64) (sum float64) {
	for _, v := range x {
		sum += math.Abs(v)
	}
	return sum
}
func L1NormInc(x []float64, n, incX int) (sum float64) {
	for i := 0; i < n*incX; i += incX {
		sum += math.Abs(x[i])
	}
	return sum
}
func Add(dst, s []float64) {
	for i, v := range s {
		dst[i] += v
	}
}
func AddConst(alpha float64, x []float64) {
	for i := range x {
		x[i] += alpha
	}
}
func CumSum(dst, s []float64) []float64 {
	if len(s) == 0 {
		return dst
	}
	dst[0] = s[0]
	for i, v := range s[1:] {
		dst[i+1] = dst[i] + v
	}
	return dst
}
func CumProd(dst, s []float64) []float64 {
	if len(s) == 0 {
		return dst
	}
	dst[0] = s[0]
	for i, v := range s[1:] {
		dst[i+1] = dst[i] * v
	}
	return dst
}
func Div(dst, s []float64) {
	for i, v := range s {
		dst[i] /= v
	}
}
func DivTo(dst, s, t []float64) []float64 {
	for i, v := range s {
		dst[i] = v / t[i]
	}
	return dst
}
func L1Dist(s, t []float64) float64 {
	var norm float64
	for i, v := range s {
		norm += math.Abs(t[i] - v)
	}
	return norm
}
func LinfDist(s, t []float64) float64 {
	var norm float64
	if len(s) == 0 {
		return 0
	}
	norm = math.Abs(t[0] - s[0])
	for i, v := range s[1:] {
		absDiff := math.Abs(t[i+1] - v)
		if absDiff > norm || math.IsNaN(norm) {
			norm = absDiff
		}
	}
	return norm
}