package adapter

import "math"

// L2Norm returns a new slice with the vector normalized to unit length.
// If the vector has zero magnitude it is returned unchanged.
func L2Norm(v []float32) []float32 {
	var sum float64
	for _, x := range v {
		sum += float64(x) * float64(x)
	}
	if sum == 0 {
		out := make([]float32, len(v))
		copy(out, v)
		return out
	}
	norm := float32(math.Sqrt(sum))
	out := make([]float32, len(v))
	for i, x := range v {
		out[i] = x / norm
	}
	return out
}