Charts / Swift 3.0 - fatal error: Index out of range - ios

Question

Recently I added https://github.com/danielgindi/Charts to my project where I have a segmentControl with time range (1D, 3M, 1Y, 5Y) to perform network call and fetch data from Yahoo.
First, I had to add a method for my String values for x-axis with the following:
class XAxisStringValueFormatter: NSObject, IAxisValueFormatter {
private var sValues: [String] = []
init(values: [String]) {
sValues = values
}
func stringForValue(_ value: Double, axis: AxisBase?) -> String {
return sValues[Int(value)]
}
}
In my LineChartViewController, I have a delegate for the timeRange change to perform my networkCall:
func networkCall(range: ChartRange) {
let symbol = self.symbol
YahooFinanceApiClient.requestEquityChartpoints(symbol: symbol, range: range, onSuccess: { chartpts in
self.createLineChart(range: range, chartpoints: chartpts)
}, onError: { error in
print("Error: \(error.localizedDescription)")
})
}
Here is my create Line ChartView:
func createLineChart(range: ChartRange, chartpoints: [EquityChartpoint]) {
// set data
var xValues: [String] = []
var yValues: [Double] = []
for object in chartpoints {
switch range {
case .OneDay:
let x = Formatters.sharedInstance.stringFromHours(date: object.date)
xValues.append(x!)
case .ThreeMonth, .OneYear, .FiveYear:
let x = Formatters.sharedInstance.stringFromDate(date: object.date)
xValues.append(x!)
}
let y = object.close
yValues.append(y!)
}
// charting
let formatter: XAxisStringValueFormatter = XAxisStringValueFormatter(values: xValues)
let xaxis: XAxis = XAxis()
var dataEntries: [ChartDataEntry] = []
for i in 0..<xValues.count {
let dataEntry = ChartDataEntry(x: Double(i), y: yValues[i], data: xValues as AnyObject)
dataEntries.append(dataEntry)
}
xaxis.valueFormatter = formatter
let lineChartDataSet = LineChartDataSet(values: dataEntries, label: "Price")
let data: LineChartData = LineChartData(dataSets: [lineChartDataSet])
self.lineChartView.data = data
self.lineChartView.xAxis.valueFormatter = xaxis.valueFormatter
}
I have a Fatal Error - Index out of range when I moved from "3M" to "1Y". I checked the xValues count to match yValues for each time range. It appears the error arrived at that xAxisStringValueFormatter where yValues count does not match the xValues. Seems strange to me. Anyone has some idea what I did wrong?

Answer 1

Index out of range for line chart graph or Bar chart Graph. When the reading is 1. Please do the following changes in the Protocol of IAxisValueFormatter.
func stringForValue(_ value: Double, axis: AxisBase?) -> String {
return myArr[Int(value) % myArr.count]
}

Answer 2

func stringForValue(_ value: Double, axis: AxisBase?) -> String {
let a = ""
if(myArr.count>0)
{
return myArr[Int(value) % myArr.count]
}
return a
}