How To Calculate Moving Average Convergence Divergence (MACD) in Swift?

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func calculateMACD(data: [Double], shortPeriod: Int, longPeriod: Int, signalPeriod: Int) -> [Double] {
    
    let shortEMA = calculateEMA(data: data, period: shortPeriod)
    let longEMA = calculateEMA(data: data, period: longPeriod)
    
    var macdLine = [Double]()
    
    for i in 0..<shortEMA.count {
        let macdValue = shortEMA[i] - longEMA[i]
        macdLine.append(macdValue)
    }
    
    let signalLine = calculateEMA(data: macdLine, period: signalPeriod)
    
    return signalLine
}

func calculateEMA(data: [Double], period: Int) -> [Double] {
    var emaValues = [Double]()
    var k = 2.0 / (Double(period) + 1.0)
    
    emaValues.append(data[0])
    
    for i in 1..<data.count {
        let ema = (data[i] * k) + (emaValues[i - 1] * (1 - k))
        emaValues.append(ema)
    }
    
    return emaValues
}

// Example input data
let data = [10.0, 12.0, 14.0, 16.0, 18.0, 20.0, 22.0, 24.0, 26.0, 28.0]

// Parameters
let shortPeriod = 12
let longPeriod = 26
let signalPeriod = 9

// Calculate MACD
let macd = calculateMACD(data: data, shortPeriod: shortPeriod, longPeriod: longPeriod, signalPeriod: signalPeriod)

print(macd)