fatal error: Double value cannot be converted to Int because it is either infinite or NaN

[digidhamu]

When I use LineChart APIs, I am getting fatal error at ChartUtils.swift @ line 53.

fatal error: Double value cannot be converted to Int because it is either infinite or NaN

    internal class func decimals(_ number: Double) -> Int
    {
        if number.isNaN || number.isInfinite || number == 0.0
        {
            return 0
        }

        let i = roundToNextSignificant(number: Double(number))
        **return Int(ceil(-log10(i))) + 2**
    }

[digidhamu]

I am now checking array elements count before passing to Charts API as workaround.

[pmairoldi]

What double value are you passing? I'll write some test cases to try to fix this.

[digidhamu]

@petester42 I was passing array of Double but array is empty.

[pmairoldi]

so let x:[Double] = [] or an array of empty values?

[digidhamu]

let x: [Double] = [] is passed without appending.

[pmairoldi]

Then my assumption would be that the function would never be called. Can you provide the snippit you use to create this chart so I can reproduce it in my environment?

[digidhamu]

Previous: this produces fatal error when array is empty
setChart(lineChartSpeed, dataPoints: counterDrive, values: speedDrive)

Current one with condition to avoid this fatal error

if counterDrive.count > 0 {
     setChart(lineChartSpeed, dataPoints: counterDrive, values: speedDrive)
}

Function to set the graph datasets

fileprivate func setChart(_ lineChartView: LineChartView, dataPoints: [Double], values: [Double]) {

    var dataEntries: [ChartDataEntry] = []

    for i in 0..<dataPoints.count {
      let dataEntry = ChartDataEntry(x: Double(i), y: values[i])
      dataEntries.append(dataEntry)
    }

    let lineChartDataSet = LineChartDataSet(values: dataEntries, label: "Speed")
    lineChartDataSet.setColor(UIColor.blue)
//    lineChartDataSet.drawCubicEnabled = true
    lineChartDataSet.mode = .cubicBezier
    lineChartDataSet.drawCirclesEnabled = false
    lineChartDataSet.lineWidth = 1.0
    lineChartDataSet.circleRadius = 5.0
    lineChartDataSet.highlightColor = UIColor.red
    lineChartDataSet.drawHorizontalHighlightIndicatorEnabled = true

    var dataSets = [IChartDataSet]()
    dataSets.append(lineChartDataSet)

    let lineChartData = LineChartData(dataSets: dataSets)

    lineChartView.data = lineChartData
  }

[pmairoldi]

Yup confirmed bug. Should be a simple fix.

[digidhamu]

@petester42 Thanks for this update and will wait for the fix.

[pmairoldi]

fixed by #1558

[josman185]

I have found the solution to this. Just be careful with the implementation of this pod, specifically in this method:

func setChart(dataPoints: [String], values: [Double]) {
...
...
let chartDataSet = LineChartDataSet(yVals: dataEntries, label: "")
data = LineChartData(xVals: dataPoints, dataSet: chartDataSet)
}

Here the new implementation:
Make sure you are passing the "chartDataSet" instead of the "dataPoints".

func setChart(_ dataPoints: [String], values: [Double]) {
...
...
let chartDataSet = LineChartDataSet(values: dataEntries, label: "")
data = LineChartData(dataSet: chartDataSet)
}

I was making a big mistake passing the "dataPoints" instead of the "chartDataSet" values. Obviously Xcode doesn´t show any error until you run your code.
Hope this helps.