Ios 如何从Swift中的无限数中导出值？

我下面的函数偶尔会产生一个无穷大的数。我原以为我可以使用下面的舍入函数来避免使用无限数…换句话说，1.333333333INF舍入为1.33，但是编译器仍然将INF的结果视为无限，我如何舍入，以便我仍然可以在这里输出值？具体地说，我正在尝试编码为JSON并得到以下错误：

metadata ERROR=invalidValueinf，Swift.EncodingError.ContextcodingPath:[Watch_Extension.HockeyTrackerMetadata.CodingKeys in _B2A710AF20490DAF638D1E0A01E4982.maximumCapableSpeed]，调试说明：无法在JSON中直接编码Double.infinity。使用JSONECODER.NonconformingFlogencodingStrategy.convertToString指定值的编码方式。underlineError:nil

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无穷大值意味着该值是正无穷大或负无穷大，可能是因为它是被零除或类似数学运算的结果。这并不意味着该值是非终止小数

确保maxHeartRateUnwrapped和AverageTimeHeartRateUnwrapped不为零

//Calculation  
 func calculateMaximumAndAverageSkatingEfficiency() {

        let heartRateUnit:HKUnit = HKUnit(from: "count/min")
        let heartRatesAsDouble = heartRateValues.map { $0.quantity.doubleValue(for: heartRateUnit)}
        let maxHeartRate = heartRatesAsDouble.max()
        guard let maxHeartRateUnwrapped = maxHeartRate else { return }

        maximumEfficiencyFactor = ((1760.0 * (maxSpeed / 60)) / maxHeartRateUnwrapped).round(to: 2)

        guard let averageIceTimeHeartRateUnwrapped = averageIceTimeHeartRate else { return }

        averageEfficiencyFactor = ((1760.0 * (averageSpeed / 60)) / averageIceTimeHeartRateUnwrapped).round(to: 2)

    }

//Round extension I am using
extension Double {

    func round(to places: Int) -> Double {
        let divisor = pow(10.0, Double(places))
        return Darwin.round(self * divisor) / divisor
    }

}

//Usage 
  if let averageEfficiencyFactorUnwrapped = averageEfficiencyFactor {
            metadata.averageEfficiencyFactor = averageEfficiencyFactorUnwrapped.round(to: 2)
        }