Last Value doesn't appear in barCharts and lineCharts

[ajimenezjulio]

I have some troubles with the library, when I create a barChart I have to add an extra value to my values array in order to show all my original values, and in the lineChart the last value appears in the line graph but it doesn't have its value above the point like the others.

I let you my code and some pictures showing the problem:

BarChart: My xAxis have a custom format showing months.

override func viewDidLoad() {
    super.viewDidLoad()

    let unitsSold = [20.0, 4.0, 6.0, 3.0, 12.0, 16.0, 4.0, 18.0, 2.0, 4.0, 5.0, 4.0]
    max = unitsSold.maxElement()        

    setChart(unitsSold)        
}


func setChart(values: [Double]) {

    let formato:BarChartFormatter = BarChartFormatter()
    let xaxis:XAxis = XAxis()

    barChartView.noDataText = "You need to provide data for the chart."

    var dataEntries: [BarChartDataEntry] = []

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

        formato.stringForValue(Double(i), axis: xaxis)
    }

    xaxis.valueFormatter = formato

    let chartDataSet = BarChartDataSet(values: dataEntries, label: "Units Sold")
    chartDataSet.colors = ChartColorTemplates.joyful()

    barChartView.fitBars = true //Para que las barras inicial y final se muestren completas
    barChartView.xAxis.valueFormatter = xaxis.valueFormatter
    barChartView.xAxis.labelPosition = .Bottom
    barChartView.leftAxis.axisMinimum = 0
    barChartView.leftAxis.axisMaximum = max + 2
    barChartView.rightAxis.enabled = false
    barChartView.drawValueAboveBarEnabled = false
    barChartView.descriptionText = ""
    barChartView.xAxis.drawGridLinesEnabled = false
    barChartView.animate(xAxisDuration: 1.0, yAxisDuration: 1.0)

    let chartData = BarChartData()
    chartData.addDataSet(chartDataSet)
    barChartView.data = chartData
}

LineChart: My xAxis have a custom format showing months.

override func viewDidLoad() {
    super.viewDidLoad()

    let unitsSold = [20.0, 4.0, 6.0, 3.0, 12.0, 16.0]
    max = unitsSold.maxElement()

    setChart(unitsSold)   
}

func setChart(values: [Double]) {

    let formato:BarChartFormatter = BarChartFormatter()
    let xaxis:XAxis = XAxis()

    var dataEntries: [ChartDataEntry] = []

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

        formato.stringForValue(Double(i), axis: xaxis)
    }

    xaxis.valueFormatter = formato

    let lineChartDataSet = LineChartDataSet(values: dataEntries, label: "Units Sold")
    lineChartDataSet.colors = ChartColorTemplates.joyful()
    lineChartDataSet.circleColors = ChartColorTemplates.joyful()
    lineChartDataSet.drawCircleHoleEnabled = false


    let lineChartData = LineChartData( dataSet: lineChartDataSet)
    lineChartData.setValueFont(UIFont(name: "HelveticaNeue-Light", size: 7))

    lineChartView.fitScreen()
    lineChartView.xAxis.labelPosition = .Bottom
    lineChartView.xAxis.axisMaximum = Double(values.count) 
    lineChartView.leftAxis.axisMinimum = 0
    lineChartView.leftAxis.axisMaximum = max + 3
    lineChartView.rightAxis.enabled = false
    lineChartView.descriptionText = ""
    lineChartView.xAxis.drawGridLinesEnabled = false
    lineChartView.animate(xAxisDuration: 1.0, yAxisDuration: 1.0)
    lineChartView.xAxis.valueFormatter = xaxis.valueFormatter

    lineChartView.data = lineChartData
 }

The responses are: For barChart December doesn't appear and in lineChart the last value doesn't show its value above it, I hope someone can help.

[chuynadamas]

Hi @ajimenezjulio

Regarding the bars i have the same problem.

Are you using fitBars? If yes,I guess that the problem is that in the function swift internal override func calcMinMax() over the class BarChartView they have the following calculate

        if fitBars
        {
            _xAxis.calculate(
                min: data.xMin - data.barWidth / 2.0,
                max: data.xMax - data.barWidth / 2.0)
        }
        else
        {
            _xAxis.calculate(min: data.xMin, max: data.xMax)
        }

In my case, I'm using the fitbars property, but I guess that we need to add instead of subtract the size of the barWidth/2.0 to the data.xMax this to increase the value of the range to get the extra space on the chart. In other hand this jus fix the problem with the fitBars, but I guess that the problem on the following case is about the way the library calculate the space for the groups of charts.

@danielgindi @PhilJay Could you guys take a look of what I'm saying above.

_FYI every group of charts has the same number of bars, so the library isn't drawing the rest of the chart for the last group also i'm using fitBars property_

[ajimenezjulio]

O: @chuynadamas you are right changing the "-" symbol to "+" it solves the problem with the barChart graph:

if fitBars {
                _xAxis.calculate(
                min: data.xMin - data.barWidth / 2.0,
                max: data.xMax + data.barWidth / 2.0)
        }

[liuxuan30]

@ajimenezjulio is it Chart 3.0?

@chuynadamas you post this screenshot in #1359 (comment), are the same issue?

[chuynadamas]

Hey @liuxuan30,

Yes, this is 3.0 and no, there is a different issue. #1359 is about the positions of the labels.

Thanks in advance.

[ajimenezjulio]

Yep the problem #1359 is different.

I think that the problem is in the function that draws the value, similar to "drawValues" in barChart but in lineChart it doesn't exist, finding where the library draws the values for its respective point in the graph we can solve the issue. The question is where it is?.

[gw-tan]

I faced this issue as well with the LineChart. I made a temporary fix (not sure if this is the correct location to fix this) that works well.

Renderers -> LineChartRenderer.swift -> line 536 ( drawValues )

for j in _xBounds.min.stride(to: Int(ceil(Double(_xBounds.max - _xBounds.min) * phaseX + Double(_xBounds.min))) + 1, by: 1)

add the +1 to the calculation, solves the problem. Anyone can verify if this should be the fix for the problem?

this is out of topic but, drawing a bezier curve line chart has the same problem as well. The last point is not connected to the rest of the curve.

[ajimenezjulio]

Holy crap! you're incredible @FatsGW modifying that line solves the problem with the last value in lineChart, thank you!!!

[danielgindi]

@PhilJay ?

[PhilJay]

Just checked on Android, could not reproduce the issue. Maybe this is iOS only?

[danielgindi]

This is already fixed by one of the PRs, please re-check.

[ghost]

I faced this issue as well with the LineChart. I made a temporary fix (not sure if this is the correct location to fix this) that works well.
Renderers -> LineChartRenderer.swift -> line 536 ( drawValues )
for j in _xBounds.min.stride(to: Int(ceil(Double(_xBounds.max - _xBounds.min) * phaseX + Double(_xBounds.min))) + 1, by: 1)
add the +1 to the calculation, solves the problem. Anyone can verify if this should be the fix for the problem?

Same Problem I have. Above fix is not working for me
Here is my code at Renderers -> LineChartRenderer.swift -> line 536 ( drawValues )
for j in stride(from: _xBounds.min, through: min(_xBounds.min + _xBounds.range, _xBounds.max), by: 1)
Please let me know How I have to change the code to fix the issue?
@danielgindi @FatsGW