How to set the axis options of iOS Radar Chart? - ios

Question

I would like to draw radar charts with iOS Charts library by danielgindi, but I cannot figure out how to use options, especially the options regarding the axis.
It does work usually, but when I set the list of variables (array) as [100.0, 100.0, 100.0, 100.0, 100.0], it shows too zoomed a chart like this:
Instead, when I set array as [90.0, 80.0, 90.0, 70.0, 20.0], the interval of the grid lines is not 20 in spite of my code:
Judging from these outputs, the cause of the problem seems to be the options for the axis. However, I could not to solve this problem myself.
How do you fix the size of the chart and the range of the axis, and draw grid lines just as you like?
I use Xcode 8.1 / swift 2.3 / Charts 2.3.1.
import UIKit
import Charts
class ViewController: UIViewController {
#IBOutlet weak var radarChartView: RadarChartView!
//Label
let subjects = ["English", "Math", "Physics", "Chemistry", "Biology"]
//Points
let array = [100.0, 100.0, 100.0, 100.0, 100.0]
override func viewDidLoad() {
super.viewDidLoad()
setChart(subjects, values: array)
print("array:")
print(array)
}
func setChart(dataPoints: [String], values: [Double]) {
radarChartView.noDataText = "You need to provide data for the chart."
var dataEntries: [ChartDataEntry] = []
for i in 0..<dataPoints.count {
let dataEntry = ChartDataEntry(value: values[i], xIndex: i)
dataEntries.append(dataEntry)
}
let chartDataSet = RadarChartDataSet(yVals: dataEntries, label: "Units Sold")
let chartData = RadarChartData(xVals: subjects, dataSet: chartDataSet)
radarChartView.data = chartData
//Options of radarChart
radarChartView.sizeToFit()
radarChartView.descriptionText = ""
//Options for the axis from here. The range is 0-100, the interval is 20
radarChartView.yAxis.labelCount = 6
radarChartView.yAxis.axisMinValue = 0.0
radarChartView.yAxis.axisMaxValue = 100.0
radarChartView.rotationEnabled = false
chartDataSet.drawFilledEnabled = true
//Present the number as integer
let numberFormatter = NSNumberFormatter()
numberFormatter.generatesDecimalNumbers = false
chartDataSet.valueFormatter = numberFormatter
radarChartView.yAxis.valueFormatter = numberFormatter
//Other options
radarChartView.legend.enabled = false
radarChartView.yAxis.gridAntialiasEnabled = true
radarChartView.animate(yAxisDuration: 2.0)
}

Answer 1

I just had to set data AFTER options.
picture
func setChart(dataPoints: [String], values: [Double]) {
radarChartView.noDataText = "You need to provide data for the chart."
var dataEntries: [ChartDataEntry] = []
for i in 0..<dataPoints.count {
let dataEntry = ChartDataEntry(value: values[i], xIndex: i)
dataEntries.append(dataEntry)
}
let chartDataSet = RadarChartDataSet(yVals: dataEntries, label: "Units Sold")
//Set options...
//Then set data
let chartData = RadarChartData(xVals: subjects, dataSet: chartDataSet)
}