How to change Double value to String in barChart/swift? - ios

Question

Instead of showing the Double values in my chart I would like to show a String for each value. I still want the chart to draw from the Double values, but I want the label to show a string with a date instead. How to do this?
I´m using Daniel Cohen Gindis library.
Here is the code for my graph:
import UIKit
import Charts
class ViewController: UIViewController {
#IBOutlet var barChartView: BarChartView!
override func viewDidLoad() {
super.viewDidLoad()
//x line values
let tools = ["Saw","Sissor","Axe"
,"Hammer","Tray"]
//y line values
let values = [1.0,2.0,3.0,4.0,5.0]
setChart(tools, values: values, colors: colors)
}
func setChart(xAxisLabels: [String], values: [Double], colors: [UIColor]){
var dataEntries : [BarChartDataEntry] = []
for i in 0..<xAxisLabels.count {
let dataEntry = BarChartDataEntry(value: values[i], xIndex: i )
dataEntries.append(dataEntry)
}
barChartView.leftAxis.axisMinValue = 0.0
barChartView.leftAxis.axisMaxValue = 14.0
barChartView.data = chartData
}
}

Answer 1

You can use the String() method to convert any data type into a string.
For example:
var myDouble: Double = 1.5
print(String(myDouble)) // Prints "1.5"

Answer 2

I don't know if you still need the answer, but this may help somebody who struggles with the same problem :)
First of all, you need to make a ValueFormatter class for your xAxis.
xAxis.valueFormatter = XAxisValueFormatter()
And then you have to put the following in your new class:
class XAxisValueFormatter: NSObject, IAxisValueFormatter {
func stringForValue(_ value: Double, axis: AxisBase?) -> String {
let dateFormatterPrint = DateFormatter()
dateFormatterPrint.dateFormat = "HH:mm:ss"
let date = Date(timeIntervalSince1970: value)
let time = dateFormatterPrint.string(from: date)
return time
}
}