画面遷移後のCollectionViewが表示される前にIndex out of rangeエラーが出てしまう

前提・実現したいこと

Swiftで友達を登録・管理するアプリを作っており、データをCollectionViewに表示したいです。
Realm Swiftを使っており、名前や写真に加えてChartsでレーダーチャートも登録・表示したいです。
エラーは、情報入力画面で登録のボタンを押すと、CollectionViewに戻らずに"Index out of range"が出ます。
毎回ではなく、データ登録が何回かうまく行く時もあり、またCollectionViewのCellからレーダーチャート表示を除くとエラーは出ません。
原因究明方法を教えていただけると嬉しいです。

発生している問題・エラーメッセージ

Fatal error: Index out of range: file Swift/ContiguousArrayBuffer.swift, line 444

エラーはChartsのRadarChartRenderer.swiftファイル124行目にに出ます。

let accessibilityLabel = accessibilityAxisLabelValueTuples[j].0

該当のソースコード

swift
1import UIKit
2import RealmSwift
3
4class Mate: Object {
5    @objc dynamic var id = ""
6    @objc dynamic var name = ""
7    @objc dynamic var photo = Data()
8    @objc dynamic var paranum = 6
9    @objc dynamic var lab_1 = ""
10    @objc dynamic var lab_2 = ""
11    @objc dynamic var lab_3 = ""
12    @objc dynamic var lab_4 = ""
13    @objc dynamic var lab_5 = ""
14    @objc dynamic var lab_6 = ""
15    @objc dynamic var val_1: Double = 0
16    @objc dynamic var val_2: Double = 0
17    @objc dynamic var val_3: Double = 0
18    @objc dynamic var val_4: Double = 0
19    @objc dynamic var val_5: Double = 0
20    @objc dynamic var val_6: Double = 0
21}

swift
1import UIKit
2import Charts
3import RealmSwift
4
5class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
6
7    @IBOutlet weak var collectionView: UICollectionView!
8    
9    let realm = try! Realm()
10    var mates = try! Realm().objects(Mate.self)
11        
12    override func viewDidLoad() {
13        super.viewDidLoad()
14        // Do any additional setup after loading the view.
15        collectionView.dataSource = self
16        mates = try! Realm().objects(Mate.self)
17    }
18    
19    //セルの数を設定
20    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
21        return mates.count
22    }
23    
24    //セルの情報を設定
25    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
26        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CollectionViewCell", for: indexPath) as! CollectionViewCell
27        let mate = mates[indexPath.row]
28        var uiImage: UIImage? = UIImage(data: mate.photo as Data)
29        let vs = [mate.val_1, mate.val_2, mate.val_3, mate.val_4, mate.val_5, mate.val_6]
30        let ls = [mate.lab_1, mate.lab_2, mate.lab_3, mate.lab_4, mate.lab_5, mate.lab_6]
31        let no = mate.paranum
32        cell.setup(name: mate.name, icon: uiImage!, vals: vs, labs: ls, num: no)
33        return cell
34    }
35}

swift
1import UIKit
2import Charts
3
4class CollectionViewCell: UICollectionViewCell {
5    @IBOutlet weak var cellName: UILabel!
6    @IBOutlet weak var cellImage: UIImageView!
7    @IBOutlet weak var cellChart: RadarChartView!
8    
9    func setup(name: String, icon: UIImage, vals: [Double], labs: [String], num: Int){
10        cellName.text = name
11        cellImage.image = icon
12        setChart(values: vals, labels: labs, paraNum: num)
13    }
14    
15    func setChart(values: [Double], labels: [String], paraNum: Int){
16        var dataEntries: [RadarChartDataEntry] = []
17        for i in 0..<paraNum {
18            let dataEntry = RadarChartDataEntry(value: values[i], data: i)
19            dataEntries.append(dataEntry)
20        }
21        let set = RadarChartDataSet(dataEntries)
22        let xAxis = cellChart.xAxis
23        let chartFormatter = RadarChartFormatter(labels: labels)
24        xAxis.valueFormatter = chartFormatter
25        cellChart.xAxis.valueFormatter = xAxis.valueFormatter
26        cellChart.data = RadarChartData(dataSet: set)
27    }
28}
29
30private class RadarChartFormatter: NSObject, IAxisValueFormatter {
31    
32    var labels: [String] = []
33    
34    func stringForValue(_ value: Double, axis: AxisBase?) -> String {
35        if Int(value) < labels.count {
36            return labels[Int(value) % labels.count]
37        }else{
38            return String("")
39        }
40    }
41    init(labels: [String]) {
42        super.init()
43        self.labels = labels
44    }
45}

swift
1import UIKit
2import RealmSwift
3import Charts
4
5class InputViewController: UIViewController, UIImagePickerControllerDelegate & UINavigationControllerDelegate {
6
7    @IBOutlet weak var nameLabel: UILabel!
8    @IBOutlet weak var imageView: UIImageView!
9    @IBOutlet weak var radarChart: RadarChartView!
10    @IBOutlet weak var paraView: UIView!
11    
12    var inputPhoto = UIImage(named: "sample")
13    var inputName = ""
14    var inputLab_1 = ""
15    var inputLab_2 = ""
16    var inputLab_3 = ""
17    var inputLab_4 = ""
18    var inputLab_5 = ""
19    var inputLab_6 = ""
20    var inputVal_1: Double = 0
21    var inputVal_2: Double = 0
22    var inputVal_3: Double = 0
23    var inputVal_4: Double = 0
24    var inputVal_5: Double = 0
25    var inputVal_6: Double = 0
26    var labs = ["", "", "", "", "", ""]
27    var vals:[Double] = [0, 0, 0, 0, 0, 0]
28    
29    override func viewDidLoad() {
30        super.viewDidLoad()
31        nameLabel.text = inputName
32        imageView.image = inputPhoto
33        labs = [inputLab_1, inputLab_2, inputLab_3, inputLab_4, inputLab_5, inputLab_6]
34        vals = [inputVal_1, inputVal_2, inputVal_3, inputVal_4, inputVal_5, inputVal_6]
35        setChart(values: vals, labels: labs, paraNum: inputParaNum)
36    }
37        
38    //登録ボタン
39    @IBAction func okBtm(_ sender: Any) {
40        let realm = try! Realm()
41        let newData = Mate()
42        newData.name = inputName
43        newData.photo = (imageView.image?.jpegData(compressionQuality: 0.25))! as Data
44        newData.paranum = inputParaNum
45        newData.lab_1 = labs[0]
46        newData.lab_2 = labs[1]
47        newData.lab_3 = labs[2]
48        newData.lab_4 = labs[3]
49        newData.lab_5 = labs[4]
50        newData.lab_6 = labs[5]
51        newData.val_1 = vals[0]
52        newData.val_2 = vals[1]
53        newData.val_3 = vals[2]
54        newData.val_4 = vals[3]
55        newData.val_5 = vals[4]
56        newData.val_6 = vals[5]
57        try! realm.write {
58            realm.add(newData)
59        }
60        self.dismiss(animated: true, completion: nil)
61    }
62            
63private class RadarChartFormatter: NSObject, IAxisValueFormatter {
64    
65    var labels: [String] = []
66    
67    func stringForValue(_ value: Double, axis: AxisBase?) -> String {
68        if Int(value) < labels.count {
69            return labels[Int(value)]
70        }else{
71            return String("")
72        }
73    }
74    
75    init(labels: [String]) {
76        super.init()
77        self.labels = labels
78    }
79}

swift
1import UIKit
2
3class ParaViewController: UIViewController {
4
5    @IBOutlet weak var lab_1: UITextField!
6    @IBOutlet weak var lab_2: UITextField!
7    @IBOutlet weak var lab_3: UITextField!
8    @IBOutlet weak var lab_4: UITextField!
9    @IBOutlet weak var lab_5: UITextField!
10    @IBOutlet weak var lab_6: UITextField!
11    @IBOutlet weak var val_1: UITextField!
12    @IBOutlet weak var val_2: UITextField!
13    @IBOutlet weak var val_3: UITextField!
14    @IBOutlet weak var val_4: UITextField!
15    @IBOutlet weak var val_5: UITextField!
16    @IBOutlet weak var val_6: UITextField!
17    
18    var childVals:[Double] = [0, 0, 0, 0, 0, 0]
19    var childLabs = ["A", "B", "C", "D", "E", "F"]
20    var childParaNum = 6
21    
22    override func viewDidLoad() {
23        super.viewDidLoad()
24    }
25    
26    override func viewWillAppear(_ animated: Bool) {
27        let parent = self.parent as! InputViewController
28        childVals = parent.vals
29        childLabs = parent.labs
30        childParaNum = parent.inputParaNum
31    }
32
33    @objc func changeDatas(){
34        changeData(text: val_1.text!, dataNum: 0)
35        changeData(text: val_2.text!, dataNum: 1)
36        changeData(text: val_3.text!, dataNum: 2)
37        changeData(text: val_4.text!, dataNum: 3)
38        changeData(text: val_5.text!, dataNum: 4)
39        changeData(text: val_6.text!, dataNum: 5)
40        let parent = self.parent as! InputViewController
41        parent.setChart(values: childVals, labels: childLabs, paraNum: childParaNum)
42        parent.vals = childVals
43    }
44    
45    func changeData(text:String, dataNum:Int){
46        if text == "" {
47            childVals[dataNum] = 0
48        }else{
49            childVals[dataNum] = Double(text)!
50        }
51    }
52    
53    func changeLabels(){
54        childLabs[0] = String(lab_1.text!)
55        childLabs[1] = String(lab_2.text!)
56        childLabs[2] = String(lab_3.text!)
57        childLabs[3] = String(lab_4.text!)
58        childLabs[4] = String(lab_5.text!)
59        childLabs[5] = String(lab_6.text!)
60        let parent = self.parent as! InputViewController
61        parent.labs = childLabs
62    }