Swift - interpolation function

InterpolationAlgorithm.swift

import simd

static func interpolate(desiredX: inout [Float], y: inout [Float]) -> [Float] {
    
    let n = desiredX.count - 1
    let stride = vDSP_Stride(1) //Int Type Alias
    let denominator = Float(n) / Float(y.count - 1)
    let control: [Float] = desiredX.map {
        let x = Float($0) / denominator
        let smoothStep = Float(simd_smoothstep(0, 1, simd_fract(x)))
        return Float(floor(x)) + smoothStep
    }
    
    var desiredY = [Float](repeating: 0, count: desiredX.count)
    
    vDSP_vlint(&y,
               control, stride,
               &desiredY, stride,
               UInt(desiredX.count),
               UInt(y.count))
    
    return desiredY
    
}