What are the existing links in RSI (Relative Strength Index)?

In the context of iOS development, the abbreviation RSI more often refers to Recurrent Structure Index (a type of neural network) or Release to Service Index, but not to specific "links". Perhaps you meant something else?

If you are talking about the Relative Strength Index (RSI) used in technical analysis of financial markets, it does not have a concept of "links" in the usual programming sense. RSI is calculated based on price changes, and its main components are:

• Average Gain: The average of positive price changes over a certain period.
• Average Loss: The average of absolute values of negative price changes over the same period.

The RSI formula is based on these averages:

// RSI Formula
// RS (Relative Strength) = Average Gain / Average Loss
// RSI = 100 - (100 / (1 + RS))

Perhaps your question relates to using RSI in trading algorithms implemented on iOS, where there might be references to:

• Historical price data: Arrays or structures storing time series of prices (Open, High, Low, Close, Volume).
• RSI calculation parameters: An integer value for the period (e.g., 14 for standard RSI).
• Functions or methods: That perform RSI calculation based on input data.
• Trading signals: Boolean variables or enumerations indicating potential entry/exit points based on RSI values (e.g., RSI > 70 - overbought, RSI < 30 - oversold).

Example of a data structure for historical prices:

struct PriceData {
    let date: Date
    let open: Double
    let high: Double
    let low: Double
    let close: Double
    let volume: Double
}

Example of usage in code for calculation:

func calculateRSI(prices: [PriceData], period: Int) -> [Double?] {
    guard prices.count > period else { return [] }

    var rsiValues: [Double?] = Array(repeating: nil, count: period)
    var gains = [Double]()
    var losses = [Double]()

    for i in 1..<prices.count {
        let change = prices[i].close - prices[i-1].close
        if change > 0 {
            gains.append(change)
            losses.append(0)
        } else {
            gains.append(0)
            losses.append(abs(change))
        }
    }

    // Implementation of average and RSI calculation...
    return rsiValues
}