average.swift

extension Sequence where Element == Float {
    // average is a vector space operation
    func average() -> Element {
        let one = Float(1.0)
                
        var mean = Element.zero
        var n = Float(0.0)

        for x in self {
            n += one
            mean = mean + (x - mean) / n
        }
        return mean
    }
}

extension Sequence where Element: SIMD, Element.Scalar: FloatingPoint {
    // average is a vector space operation
    func average() -> Element {
        let one = Element.one[0]
                
        var mean = Element.zero
        var n = mean[0]

        for x in self {
            n += one
            mean = mean + (x - mean) / n
        }
        return mean
    }
}