Combined chart (Scatter and Line) producing random results.

[cnnamoca]

• [✓] I've read, understood, and done my best to follow the *CONTRIBUTING guidelines.

What did you do?

Create a combined Scatter and Line Chart.

What did you expect to happen?

I wanted the line to be behind the scatter plot.

What happened instead?

It actually works but for some reason, it sometimes produces the image attached randomly and I would have to restart the app or reload the view every time.

Charts Environment

3.4.0 / master
Xcode 11.2.1
Swift 5
iOS
macOS 10.15.1

Demo Project

func createCombinedChart(_ values1: [ChartDataEntry], _ values2: [ChartDataEntry], _ chartView: CombinedChartView, _ chartType: ChartType, _ isLinear: Bool, _ hasGradient: Bool) {
        
        let set1 = ScatterChartDataSet(entries: values1, label: nil)
        set1.highlightEnabled = true
        set1.highlightColor = .clear // Removes orange lines from marker
        set1.drawValuesEnabled = false
        set1.setScatterShape(.circle)
        set1.scatterShapeSize = 6.0
        set1.setColor(UIColor.white)
        
        let set2 = LineChartDataSet(entries: values2, label: nil)
        set2.highlightEnabled = false
        set2.highlightColor = .clear // Removes orange lines from marker
        set2.drawValuesEnabled = false
        set2.drawCirclesEnabled = false
        set2.circleRadius = 0.5
        set2.lineCapType = .round
        set2.lineWidth = 1
        set2.lineDashLengths = [5, 5]
        set2.mode = isLinear ? .linear : .cubicBezier
        set2.colors = [NSUIColor(named: "Purple_02")] as! [NSUIColor]
        
        let gradientColors = [UIColor.clear.cgColor, UIColor(named: "Purple_01")!.cgColor]
        let gradient = CGGradient(colorsSpace: nil, colors: gradientColors as CFArray, locations: nil)!
        
        set2.fillAlpha = 1
        set2.fill = Fill(linearGradient: gradient, angle: 90)
        set2.drawFilledEnabled = hasGradient
        
        chartView.leftAxis.drawGridLinesEnabled = true
        chartView.leftAxis.drawAxisLineEnabled = true
        chartView.leftAxis.drawLabelsEnabled = true
        chartView.leftAxis.labelFont = UIFonts.BOLD_FONT_EXTRA_SMALL
        chartView.leftAxis.labelTextColor = .white
        chartView.leftAxis.axisLineColor = .darkGray
        chartView.leftAxis.axisMinimum = 0 // Keeps the x and y minimum values on the same axis
        
        chartView.rightAxis.enabled = false
        
        chartView.xAxis.drawGridLinesEnabled = false
        chartView.xAxis.drawAxisLineEnabled = true
        chartView.xAxis.drawLabelsEnabled = true
        chartView.xAxis.labelFont = UIFonts.BOLD_FONT_EXTRA_SMALL
        chartView.xAxis.labelTextColor = .white
        chartView.xAxis.labelPosition = .bottom
        chartView.xAxis.axisLineColor = .darkGray
        chartView.xAxis.avoidFirstLastClippingEnabled = true
        
        chartView.legend.enabled = false
        chartView.chartDescription?.enabled = true
        chartView.chartDescription?.textColor = .white
        chartView.chartDescription?.font = UIFonts.BOLD_FONT_EXTRA_SMALL
        chartView.chartDescription?.text = "→ \(getAxes(chartType).x), ↑ \(getAxes(chartType).y)"
        chartView.doubleTapToZoomEnabled = false
        chartView.pinchZoomEnabled = false
                
        let data = CombinedChartData()
        data.scatterData = ScatterChartData(dataSets: [set1])
        data.lineData = LineChartData(dataSets: [set2])
        data.notifyDataChanged()
        chartView.data = data
        chartView.notifyDataSetChanged()
    }

[liuxuan30]

I suppose your x values are not sorted