Charts: Right Y-Axis values displaying incorrectly in LineChartDemo

[adriansoghoian]

Thanks for an awesome library, my app is using it extensively to plot stock market related data. When the app launches, I'll send a note in case you'd like to take a look.

I currently have a strange bug where the Y-axis values are being plotted incorrectly -- it looks like they're being slightly offset.

I'm not doing any custom scaling with the data. Here are the relevant code snippets below:

func setChartDefaults() {
    // No data view
    self.lineChartView!.noDataText = ""
    self.lineChartView!.descriptionText = ""
    self.lineChartView!.noDataTextDescription = ""

    // Legend
    self.lineChartView!.legend.enabled = false


    // Interaction
    self.lineChartView!.setScaleEnabled(true)
    self.lineChartView!.pinchZoomEnabled = true
    self.lineChartView!.doubleTapToZoomEnabled = true

    // Background
    self.lineChartView!.drawGridBackgroundEnabled = true
    self.lineChartView!.gridBackgroundColor = UIColor.clearColor()
    self.lineChartView!.backgroundColor = UIColor.clearColor()

    // Borders
    self.lineChartView!.borderColor = UIColor.clearColor()
    self.lineChartView!.drawBordersEnabled = false

    // Format x axis
    self.lineChartView!.xAxis.enabled = true
    self.lineChartView!.xAxis.labelPosition = .Bottom
    self.lineChartView!.xAxis.drawAxisLineEnabled = false
    self.lineChartView!.xAxis.drawGridLinesEnabled = false
    self.lineChartView!.xAxis.labelFont = UIFont.TriggerFontSemiBold(11)
    self.lineChartView!.xAxis.axisLineWidth = 1.0
    self.lineChartView!.xAxis.spaceBetweenLabels = 9
    self.lineChartView!.xAxis.avoidFirstLastClippingEnabled = true

    // Remove left axis
    self.lineChartView!.leftAxis.enabled = false
    self.lineChartView!.leftAxis.drawAxisLineEnabled = false
    self.lineChartView!.leftAxis.spaceTop = 0.5
    self.lineChartView!.leftAxis.startAtZeroEnabled = false
    self.lineChartView!.leftAxis.spaceBottom = 0.4

    // Add right axis
    self.lineChartView!.rightAxis.enabled = true
    self.lineChartView!.rightAxis.drawAxisLineEnabled = true
    self.lineChartView!.rightAxis.startAtZeroEnabled = false
    self.lineChartView!.rightAxis.drawGridLinesEnabled = true
    self.lineChartView!.rightAxis.drawAxisLineEnabled = false

    // Format right axis font
    self.lineChartView!.rightAxis.labelFont = UIFont.TriggerFontSemiBold(12)
    self.lineChartView!.rightAxis.valueFormatter = NSNumberFormatter()
    self.lineChartView!.rightAxis.valueFormatter?.maximumFractionDigits = 2
}

func setLineChartDataSetDefaults() { // Sets preferences
    self.lineChartDataSet = LineChartDataSet()
    self.lineChartData = LineChartData()

    // Color of points
    self.lineChartDataSet!.setColor(UIColor.TriggerWhiteColor())

    // Width
    self.lineChartDataSet!.lineWidth = 1.5

    // Plot circles around points
    self.lineChartDataSet!.highlightEnabled = false
    self.lineChartDataSet!.drawCirclesEnabled = false
    self.lineChartDataSet!.drawValuesEnabled = true
    self.lineChartDataSet!.drawFilledEnabled = true
}

func graph(xData: [String], yData: [Double]) {
    for i in 0..<ydata.count { 
        let dataEntry = ChartDataEntry(value: ydata[i], xIndex: i)
        self.lineChartDataSet!.addEntry(dataEntry)
    }

    self.lineChartData!.addDataSet(self.lineChartDataSet)

    for i in 0..<xdata.count {
        self.lineChartData!.addXValue(NSDate.returnCustomFormattedDateString(xdata[i]))
    }

    self.lineChartView!.data = self.lineChartData
}

Thank you in advance for any help you can provide!

[liuxuan30]

I don't see this issue on my side. And your code seems fine. What I can suggest is, try first setup up the chart, and set chartView.data at last.

If you still has the problem, could you use ChartsDemo to reproduce it and post the data set code?

[AndreasIgelCC]

Have you tried setting the axisDependency? Default ist a left dependency and I have not seen any code in the Framework to change that, if the left axis is disabled.

self.lineChartDataSet!.axisDependency = ChartYAxis.AxisDependency.Right

[liuxuan30]

Oh yeah, I remember it, @adriansoghoian does not set axis dependency when he turns off left axis and enabled the right one. based on @AndreasIgelCC's comments, I believe it's the reason.
Closing

[adriansoghoian]

Awesome, many thanks @AndreasIgelCC! Confirming that setting the axis dependency has fixed the issue.

[Rj707]

is there anyway to make the line chart look like IOS Stock App??