Set labels at RadarChartData - swift

Question

I am using Charts v3.2.2 framework by danielgindi for iOS and macOS to draw a RadarChartView. There is a github repository that provides an example xcode project including Playgrounds. One is for RadarChartView.
Following the example I can set RadarChartData with two different RadarChartDataSets
var chartView = RadarChartView(frame: rect)
let data = RadarChartData(dataSets: [set1, set2])
chartView.data = data
It shows a chart like this:
The green labels set to x-axis are numbers from 0.0 to 4.0, but they should be string labels.
I cannot figure out how to set these labels that should be drawn around the RadarChart at the end of each web line. I guess it should be something like this:
data.setLabels("London", "Paris", "Berlin", "New York", "Tokio")
But this isn't working although it is a feature of class RadarChartData to set the desired labels.
Can somebody help me with that issue?
EDIT: complete code example
import Cocoa
import Charts
import PlaygroundSupport
let r = CGRect(x: 0, y: 0, width: 400, height: 400)
var chartView = RadarChartView(frame: r)
// General settings
chartView.webColor = NSUIColor.lightGray
chartView.innerWebColor = NSUIColor.lightGray
chartView.webAlpha = 1.0
// xAxis settings
let xAxis = chartView.xAxis
xAxis.xOffset = 0.0
xAxis.yOffset = 0.0
xAxis.labelTextColor = NSUIColor.green
xAxis.drawLabelsEnabled = true
// yAxis settings
let yAxis = chartView.yAxis
yAxis.labelCount = 5
yAxis.axisMinimum = 0.0
yAxis.axisMaximum = 80.0
yAxis.drawLabelsEnabled = true
// Legend settings
let legend = chartView.legend
// ... (irrelevant)
// Description
chartView.chartDescription?.enabled = true
chartView.chartDescription?.text = "Radar demo"
chartView.chartDescription?.textColor = #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1)
// RadarChartDataEntry
let mult = 80.0
let min = 20.0
let cnt = 5
var entries1 = [RadarChartDataEntry]()
var entries2 = [RadarChartDataEntry]()
for i in 1...cnt
{
let values1 = (Double(arc4random_uniform(UInt32(mult))) + min)
entries1.append(RadarChartDataEntry(value: values1, data: "a" as AnyObject))
let values2 = (Double(arc4random_uniform(UInt32(mult))) + min)
entries2.append(RadarChartDataEntry(value: values2, data: "b" as AnyObject))
}
// RadarChartDataSet
let set1 = RadarChartDataSet(entries: entries1, label: "Last Week")
set1.drawFilledEnabled = true
set1.fillAlpha = 0.7
set1.lineWidth = 2.0
set1.drawHighlightCircleEnabled = true
set1.setDrawHighlightIndicators(false)
let set2 = RadarChartDataSet(entries: entries2, label: "This Week")
set2.drawFilledEnabled = true
set2.fillAlpha = 0.7
set2.lineWidth = 2.0
set2.drawHighlightCircleEnabled = true
set2.setDrawHighlightIndicators(false)
// RadarChartData
let data = RadarChartData(dataSets: [set1, set2])
data.setLabels("London", "Paris", "Berlin", "New York", "Tokio")
data.setDrawValues ( true )
data.setValueTextColor( NSUIColor.white )
chartView.data = data
chartView.animate(xAxisDuration: 2.0, yAxisDuration: 2.0, easingOption: .easeInBounce)
// show chartView
PlaygroundPage.current.liveView = chartView

Answer 1

You need to override IAxisValueFormatter func stringForValue(_ value: Double, axis: AxisBase?) -> String {} function.
Like below:
Step1: Customize your xAxis with custom formatter.
let xValues = ["X1", "X2", "X3", "X4", "X5", "X6", "X7", "X8", "X9", "X10"]
let chartFormatter = RadarChartFormatter(labels: xValues)
let xAxis = XAxis()
xAxis.valueFormatter = chartFormatter
self.xAxis.valueFormatter = xAxis.valueFormatter
Step2: Implement Custom formatter with below method.
private class RadarChartFormatter: NSObject, IAxisValueFormatter {
var labels: [String] = []
func stringForValue(_ value: Double, axis: AxisBase?) -> String {
if Int(value) < labels.count {
return labels[Int(value)]
}else{
return String("")
}
}
init(labels: [String]) {
super.init()
self.labels = labels
}
}
You will get below output in your RadarCharView:
Hope this will help you to get your custom labels on Radar chart!