let normalDistRandom mean stdDev = 
    let rand = new System.Random()
    let rec polarBoxMullerDist () = seq {
            let rec getRands () =
                let u = (2.0 * rand.NextDouble()) - 1.0
                let v = (2.0 * rand.NextDouble()) - 1.0
                let w = u * u + v * v
                if w >= 1.0 then
                    getRands()
                else
                    u, v, w
            let u, v, w = getRands()
            
            let scale = System.Math.Sqrt(-2.0 * System.Math.Log(w) / w)
            let x = scale * u
            let y = scale * v
            yield mean + (x * stdDev); yield mean + (y * stdDev); yield! polarBoxMullerDist ()
        }
    polarBoxMullerDist ()