如何设置 iOS 雷达图的坐标轴选项？答案

【问题标题】：How to set the axis options of iOS Radar Chart?如何设置 iOS 雷达图的坐标轴选项？
【发布时间】：2016-12-01 09:08:23
【问题描述】：

我想用 danielgindi 的 iOS 图表库绘制雷达图，但我不知道如何使用选项，尤其是关于轴的选项。

它通常可以工作，但是当我将变量列表 (array) 设置为 [100.0, 100.0, 100.0, 100.0, 100.0] 时，它显示的图表过于放大，如下所示：

相反，当我将array 设置为[90.0, 80.0, 90.0, 70.0, 20.0] 时，网格线的间隔不是20，尽管我的代码：

从这些输出来看，问题的原因似乎是轴的选项。但是，我无法自己解决这个问题。
如何固定图表的大小和轴的范围，并随意绘制网格线？

我使用 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)
}

【问题讨论】：

标签： ios swift ios-charts

【解决方案1】：

我只需要在选项之后设置数据。 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)
}

【讨论】：