Can't manage to align plots with x axis values

[richardhouta]

Hi to everyone,

I have a chart that should display on the x axis the number of days of a cycle, and the temperatures that the user filled in, the problem is that the user is not required to add a temperature every day if he doesn't want to, and I have to ignore values that are equal to 0. I looked on stack-overflow and here to properly set x-axis labels, but for some reason my plots are not properly aligned with my labels. I also noticed that in my XAxisFormatter the value returned by the stringForValue is not like I expected meaning [1, 2, 3, 4] but more like [0.5, 0.9, 1.6, 2.4] meaning that I cannot use the value convert it as Int and pull the data from my array.

Any idea what could be the problem below part of the code I wrote

ChartDataSetEntries

private func prepareDataEntries(with data: [DailyData]) -> [ChartDataEntry] {
        var dataEntries = [ChartDataEntry]()
        for (index, dailyData) in data.enumerated() {
            if dailyData.temperature > 0 {
                let temperature = String(format:"%.2f", Double(dailyData.temperature)/10)
                if let formattedTemp = Double(temperature) {
                    let chartDataEntry = ChartDataEntry(x: Double(index), y: formattedTemp)
                    dataEntries.append(chartDataEntry)
                    if ovulationDetector.hasOvulationForDay(at: index){
                        ovulation = Highlight(x: chartDataEntry.x, y: chartDataEntry.y, dataSetIndex: 0)
                    }
                }
            }
        }
        return dataEntries
    }

Setup of the XAxis

chartView.xAxis.valueFormatter = XAxisValueFormatter(with: xAxisValues)
            chartView.xAxis.labelPosition = .bottom
            chartView.xAxis.gridColor = UIColor.black.withAlphaComponent(0.15)
            chartView.xAxis.setLabelCount(totalDays, force: true)

XAxisValueFormatter

private class XAxisValueFormatter: NSObject, IAxisValueFormatter {
    private var values: [String]
    
    init(with values: [String]) {
        self.values = values
        super.init()
    }
    
    func stringForValue(_ value: Double, axis: AxisBase?) -> String {
//value cannot be used like values[Int(value)] because I get 0.4 then 0.9 etc... and I will get duplicates since both will be equal to 1
        if let index = axis?.entries.index(where: { (current) -> Bool in
            return current == value
        }) {
            return "\(index+1)"
        }else {
            return "0"
        }
    }
}

Any idea what could be the issue ?

[richardhouta]

@jjatie, @thierryH91200, @danielgindi ?

[liuxuan30]

override computeAxisValues and feed axis.entries with desired values to make them align.