iOS Charts - Single Values Not Showing Swift

iOS Charts not showing Y values

You should add data.setDrawValues(true) when you create the BarChartData:

...
let data = BarChartData(dataSet: barChartDataSet)
data.setDrawValues(true)
data.setValueFont(UIFont(name:"Lato-Regular", size:10)!)
data.setValueTextColor(UIColor(hex:UIConstants.Graphics.BrandTheme.ThemeColor))
...

For version 3.2.1 of Charts you also need to remove this line because values are not rendered if drawIconsEnabled is false

barChartDataSet.drawIconsEnabled = false

iOS Charts - single values not showing Swift

The only way I could get around this was to add an additional invisible line.

I created a clear line that started the day before and ended the day after my single values.

As long as there is a line on the chart that goes from one point to another, the other single values show.

  var singleValue = false
    for i in 0...(dataSets.count - 1) {
        if dataSets[i].values.count > 1{
            singleValue = true
        }
    }
    var data = dataSets
    if singleValue == false {
        let minNS = Calendar.current.date(byAdding: .day, value: -1, to: minNSDate as! Date)
        let maxNS =  Calendar.current.date(byAdding: .day, value: 1, to: maxNSDate as! Date)

        var dataEntries: [ChartDataEntry] = []

        let dataEntry1 = ChartDataEntry(x:Double(String(format: "%.2f",Double((minNS?.timeIntervalSince1970)!)))!,y:00.00)
        let dataEntry2 = ChartDataEntry(x:Double(String(format: "%.2f",Double((maxNS?.timeIntervalSince1970)!)))!,y:00.00)
        dataEntries.append(dataEntry1)
        dataEntries.append(dataEntry2)
        let set = LineChartDataSet(values: dataEntries, label: "")
        set.setCircleColor(UIColor.clear)
        set.circleHoleColor = UIColor.clear
        set.setColor(UIColor.white, alpha: 0.0)
        set.drawValuesEnabled = false
        data.append(set)

    }
    chart.chartDescription?.text = ""
    let chartData = LineChartData(dataSets: data)
    chart.data = chartData

iOS Charts does not show value labels when more than 3 data sets are plotted

I fixed this with one line in viewDidLoad where I first set up my chart.

_chartView.maxVisibleCount = 500;

I guess after adding the 4th data set I had more than the default value of maxVisibleCount (whatever that is) and when that happens no data labels are drawn regardless of other settings.

I figured this out when modifying my data set's drawValuesEnabled field and inside the auto complete text it said "this value is ignored when maxVisibleCount is reached".

iOS-Charts Library: x-axis labels without backing data not showing

Ok so thanks to @wingzero 's comment, I have been able to get this working. There are a few things required to do so. For simplicity's sake, I am going to explain how to get the "days of the week" labels working as I originally asked. If you follow these steps, however, you should be able to tweak them to format your chart however you like (for example, with months of the year).

1) Make sure that your chart's x-axis minimum and maximum values are set. In this case, you'd want to say: chartView.xAxis.axisMinimum = 0.0 and chartView.axisMaximum = 6.0. This is important for step 2.

2) As Wingzero alluded to, create a subclass of XAxisRenderer that allows us to grab the minimum and maximum values set in step one and determine what values should be passed to our IAxisValueFormatter subclass in step three. In this case:

class XAxisWeekRenderer: XAxisRenderer {

    override func computeAxis(min: Double, max: Double, inverted: Bool) {
        axis?.entries = [0, 1, 2, 3, 4, 5, 6]
    }

}

Make sure to pass this renderer to your chart like this: chartView.xAxisRenderer = XAxisWeekRenderer()

3) Create a subclass of IAxisValueFormatter that takes the values we passed to the chart in step two ([0, 1, 2, 3, 4, 5, 6]) and gets corresponding label names. This is what I did in my original question here. To recap:

public class CustomChartFormatter: NSObject, IAxisValueFormatter {

    var days: = ["S", "M", "T", "W", "T", "F", "S"]

    public func stringForValue(value: Double, axis: AxisBase?) -> String {
        return days[Int(value)]
    }

}

4) Set the labelCount on your graph to be equal to the number of labels you want. In this case, it would be 7. I show how to do this, along with the rest of the steps, below the last step here.

5) Force the labels to be enabled

6) Force granularity on the chart to be enabled and set granularity to 1. From what I understand, setting the granularity to 1 means that if the data your chart passes to stringForValue is not in round numbers, the chart will essentially round said data or treat it like it is rounded. This is important since if you passed in 0.5, it's possible that your stringForValue might not produce the right strings for your labels.

7) Set the value formatter on the xAxis to be the custom formatter you created in step 3.

Steps 4-7 (plus setting the formatter created in step 3) are shown below:

chartView.xAxis.labelCount = 7
chartView.xAxis.forceLabelsEnabled = true
chartView.xAxis.granularityEnabled = true
chartView.xAxis.granularity = 1
chartView.xAxis.valueFormatter = CustomChartFormatter()

Swift charts not showing value labels

Figured it out. Turns out, when you create a data set using an array of ChartDataEntry objects, the array must be immutable (let rather than var), or labels will not be shown.

Correct data not showing in ios Charts

You have changed x & y values and hence index is coming as your pie chart's value. Also, please use PieChartDataEntry.
(working code on my box)

  override func viewDidLoad() {
    super.viewDidLoad()
    let days = ["Mo", "Tu", "Wed", "Thur", "Fri", "Sat", "Sun"]
    let gross = [11.00, 90.95, 250.00, 40.90, 60.88, 99.99, 25.00]

    setChart(days: days, gross: gross)
  }

  func setChart(days: [String], gross: [Double]) {
    var dataEntries: [ChartDataEntry] = []

    for i in 0..<days.count {
      let dataEntry = PieChartDataEntry(value : gross[i], label : days[i])
      dataEntries.append(dataEntry)
    }

    let pieChartDataSet = PieChartDataSet(values: dataEntries, label: "Gross Income")
    pieChartDataSet.sliceSpace = 2.0
    let pieChartData = PieChartData(dataSets: [pieChartDataSet])

    var colors: [UIColor] = []

    for _ in 0..<days.count {
      let red = Double(arc4random_uniform(256))
      let green = Double(arc4random_uniform(256))
      let blue = Double(arc4random_uniform(256))

      let color = UIColor(red: CGFloat(red/255), green: CGFloat(green/255), blue: CGFloat(blue/255), alpha: 1)
      colors.append(color)
    }

    pieChartDataSet.colors = colors
    pieChartView.data = pieChartData
  }

Try this and let me know.

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