// Sum returns the (possibly weighted) sum of the Sample.
func (s Sample) Sum() float64 {
if s.Weights == nil {
return vec.Sum(s.Xs)
}
sum := 0.0
for i, x := range s.Xs {
sum += x * s.Weights[i]
}
return sum
}
// Weight returns the total weight of the Sasmple.
func (s Sample) Weight() float64 {
if s.Weights == nil {
return float64(len(s.Xs))
}
return vec.Sum(s.Weights)
}