Calculating variance in Swift

Variance.swift

# Calculating variance in Swift

let data = [0, 1, 5, 7, 9, 10, 14]

func variance<T: BinaryFloatingPoint>(input: Array<T>) -> T {
    let sum = input.reduce(0, +)
    let mean = sum / T(input.count)
    
    let sumOfSquaredDifferences = input.reduce(0) { $0 + (mean - $1) * (mean - $1) }

    let variance = sumOfSquaredDifferences / T(input.count)
    return variance
}

func standardDeviation<T: BinaryFloatingPoint>(input: Array<T>) -> Double {
    return sqrt(Double(variance(input: input)))
}

print(variance(input: data.map{Double($0)}))
print(standardDeviation(input: data.map{Double($0)}))