Line Chart Issue in CombinedChartView

[BertPorter]

I am creating a combination line chart and scatter chart.
The line chart is used to draw a limit outline on the graph and the scatter chart is used to plot the data. I use an array of 8 points to create the line chart.
When I iterate over the entire array, it won't display the line chart.
I had to break the data into 3 ChartDataEntry arrays in order to display the entire line chart.
Consequently I have 3 legend items that I don't know how to get rid of.
Out of curiosity I used the same array as scatter points and they display correctly (see second photo).

In Model:
let longCGLimitsChartWtsArray = [10275.0, 9702.0, 9702.0, 10694.0, 14994.1, 14994.0, 11400.0, 10275.0]
let longCGLimitsChartCGsArray = [196.9, 199.6, 218.0, 220.3, 215.7, 206.2, 196.9, 196.9]

In View Controller:

   func longCGGraphUpdate() {
    
    // Set up GG limits chart
    var longCGLimitsChartDataEntry = [ChartDataEntry]()
    for i in 0..<5 {
        let value = ChartDataEntry(x: WTBLData.sharedInstance.longCGLimitsChartCGsArray[i], y: WTBLData.sharedInstance.longCGLimitsChartWtsArray[i])
        longCGLimitsChartDataEntry.append(value)
    }
    let longCGLimitsChartValues = LineChartDataSet(values: longCGLimitsChartDataEntry, label: "")
    longCGLimitsChartValues.colors = [NSUIColor.black]
    longCGLimitsChartValues.drawCirclesEnabled = false
    longCGLimitsChartValues.drawValuesEnabled = false
    
    var longCGLimitsChartDataEntry2 = [ChartDataEntry]()
    for i in 4..<6 {
        let value = ChartDataEntry(x: WTBLData.sharedInstance.longCGLimitsChartCGsArray[i], y: WTBLData.sharedInstance.longCGLimitsChartWtsArray[i])
        longCGLimitsChartDataEntry2.append(value)
    }
    let longCGLimitsChartValues2 = LineChartDataSet(values: longCGLimitsChartDataEntry2, label: "")
    longCGLimitsChartValues2.colors = [NSUIColor.black]
    longCGLimitsChartValues2.drawCirclesEnabled = false
    longCGLimitsChartValues2.drawValuesEnabled = false
    
    var longCGLimitsChartDataEntry3 = [ChartDataEntry]()
    for i in 5..<8{
        let value = ChartDataEntry(x: WTBLData.sharedInstance.longCGLimitsChartCGsArray[i], y: WTBLData.sharedInstance.longCGLimitsChartWtsArray[i])
        longCGLimitsChartDataEntry3.append(value)
    }
    let longCGLimitsChartValues3 = LineChartDataSet(values: longCGLimitsChartDataEntry3, label: "")
    longCGLimitsChartValues3.colors = [NSUIColor.black]
    longCGLimitsChartValues3.drawCirclesEnabled = false
    longCGLimitsChartValues3.drawValuesEnabled = false

    let lineData = LineChartData()
    lineData.addDataSet(longCGLimitsChartValues)
    lineData.addDataSet(longCGLimitsChartValues2)
    lineData.addDataSet(longCGLimitsChartValues3)

     // Set up empty wt chart value
    let emptyWtChartValues = ScatterChartDataSet(values: [ChartDataEntry(x: WTBLData.sharedInstance.emptyWtLongCG, y: WTBLData.sharedInstance.wTBLPlistItems.emptyWt)], label: "Empty Wt")
    emptyWtChartValues.colors = [NSUIColor.blue]
    emptyWtChartValues.setScatterShape(.square)
    emptyWtChartValues.drawValuesEnabled = false
    
    // Set up tof wt chart value
    let tofWtChartValues = ScatterChartDataSet(values: [ChartDataEntry(x: WTBLData.sharedInstance.tOFGrossWtLongCG, y: WTBLData.sharedInstance.tOFGrossWt)], label: "TOF Wt")
    tofWtChartValues.colors = [NSUIColor.magenta]
    tofWtChartValues.setScatterShape(.triangle)
    tofWtChartValues.drawValuesEnabled = false
    
    // Set up fuel burn chart values
    var fuelBurnChartDataEntry = [ChartDataEntry]()
    for i in 0..<WTBLData.sharedInstance.fuelBurnWtsArray.count {
        let value = ChartDataEntry(x: WTBLData.sharedInstance.fuelBurnLongCGsArray[i], y: WTBLData.sharedInstance.fuelBurnWtsArray[i])
        fuelBurnChartDataEntry.append(value)
    }
    let fuelBurnChartValues = ScatterChartDataSet(values: fuelBurnChartDataEntry, label: "Fuel Burn")
    fuelBurnChartValues.colors = [NSUIColor.green]
    fuelBurnChartValues.setScatterShape(.circle)
    fuelBurnChartValues.drawValuesEnabled = false

    // Combine all scatter data chart values
    let scatterData = ScatterChartData()
    scatterData.addDataSet(emptyWtChartValues)
    scatterData.addDataSet(fuelBurnChartValues)
    scatterData.addDataSet(tofWtChartValues)

    // Combine Scatter and Line data
    let combinedData = CombinedChartData()
    combinedData.scatterData = scatterData
    combinedData.lineData = lineData
    
    longCGGraphView.data = combinedData
    
    // Refresh chart with new data
    longCGGraphView.notifyDataSetChanged()
}

[BertPorter]

I am using constants for the graph axes.

func longCGGraphSetup() {
    
    // Set up border around view
    longCGGraphView.layer.borderWidth = 2
    longCGGraphView.layer.cornerRadius = 10
    
    // Set up border around chart
    longCGGraphView.gridBackgroundColor = NSUIColor(red: 240/255.0, green: 240/255.0, blue: 240/255.0, alpha: 0.4)  // same as default except reduced alpha from 1.0 to 0.4
    longCGGraphView.drawGridBackgroundEnabled = true
    longCGGraphView.borderLineWidth = 1.0
    longCGGraphView.drawBordersEnabled = true

    // Set up chart description
    longCGGraphView.chartDescription?.text = "Longitudinal CG Station - in."
    longCGGraphView.chartDescription?.font = NSUIFont.systemFont(ofSize: 12.0)
    longCGGraphView.chartDescription?.textColor = NSUIColor.blue

    // Set up X-Axis
    longCGGraphView.xAxis.labelPosition = .bottom
    longCGGraphView.xAxis.axisMinimum = 196.0
    longCGGraphView.xAxis.axisMaximum = 222.0

    // Set up Y-Axis
    longCGGraphView.leftAxis.axisMinimum = 9000.0
    longCGGraphView.leftAxis.axisMaximum = 15500.0
    longCGGraphView.rightAxis.enabled = false
}

[liuxuan30]

I remember the line chart x values should be sorted. Random order will have troubles, as inside it's using XBound or similar thing. I wonder it won't be fixed in a short time.
but you can come up a new chart with similar render logic to get rid of the sort limit.