Multiple Line Chart, don't want to plot 0 values. Swift 2

Question

I am generating a multiple line chart using ios-charts library. (danielgindi/Charts). I am creating an array to for the x-axsis which is retrieved from Core Data and if there is no value for x week, i appended a 0.

I have an example array of (for the x values):

[[0.0,0.0,5.6,3.0,6.0,5.4,2.1,0.0,0.0,1.3,4.1,0.0],[5.2,0.0,3.2,7.0,8.9,0.0,5.0,0.0,4.6,0.0,0.0,0.0],[3.6,1.5,3.6,0.0,0.0,3.5,0.0,4.6,5.6,2.8,8.4,0.0]]

and for the y:

[Jan,Feb,March,April,May,June,July,August,Sept,Oct,Nov,Dec]

I have the following code to display these 3 lines within a line chart:

func setChart(xValues: [NSDate], valuesLineChart: [[Double]]) {
    chartView.descriptionText = ""
    chartView.noDataText = "You need to provide data for the chart."

    var dataSets : [LineChartDataSet] = [LineChartDataSet]()
    var yVals1 : [ChartDataEntry] = [ChartDataEntry]()
    for i in 0..<xValues.count {
        yVals1.append(ChartDataEntry(value: valuesLineChart[0][i], xIndex: i))
    }

    var yVals2 : [ChartDataEntry] = [ChartDataEntry]()
    for i in 0..<xValues.count {
        yVals2.append(ChartDataEntry(value: valuesLineChart[1][i], xIndex: i))
    }

    var yVals3 : [ChartDataEntry] = [ChartDataEntry]()
    for i in 0..<xValues.count {
        yVals3.append(ChartDataEntry(value: valuesLineChart[2][i], xIndex: i))
    }

    let set1 = LineChartDataSet(yVals: yVals1, label: nil)
    let set2 = LineChartDataSet(yVals: yVals2, label: nil)
    let set3 = LineChartDataSet(yVals: yVals3, label: nil)

    set1.fillColor = UniversalStatic.data.colourArrayForGraph[0]
    set2.fillColor = UniversalStatic.data.colourArrayForGraph[1]
    set3.fillColor = UniversalStatic.data.colourArrayForGraph[2]

    dataSets.append(set1)
    dataSets.append(set2)
    dataSets.append(set3)

    set1.setColor(UniversalStatic.data.colourArrayForGraph[0])
    set2.setColor(UniversalStatic.data.colourArrayForGraph[1])
    set3.setColor(UniversalStatic.data.colourArrayForGraph[2])

    set1.lineWidth = 2
    set2.lineWidth = 2
    set3.lineWidth = 2

    set1.setCircleColor(UniversalStatic.data.colourArrayForGraph[0])
    set2.setCircleColor(UniversalStatic.data.colourArrayForGraph[1])
    set3.setCircleColor(UniversalStatic.data.colourArrayForGraph[2])

    set1.drawCircleHoleEnabled = false
    set2.drawCircleHoleEnabled = false
    set3.drawCircleHoleEnabled = false

    set1.circleRadius = 5.0
    set2.circleRadius = 5.0
    set3.circleRadius = 5.0

    let data: CombinedChartData = CombinedChartData(xVals: xValues)
    data.lineData = LineChartData(xVals: xValues, dataSets: dataSets)

    chartView.data = data

}

How can I avoid plotting the 0 values?

Thanks for any help

Answer 1

Are you looking to skip the 0.0 values entirely? You can check before appending them to the array.

Perhaps you can do:

  var yVals1 : [ChartDataEntry] = [ChartDataEntry]()
  for i in 0..<xValues.count {
      if valuesLineChart[0][i] != 0.0 {
          yVals1.append(ChartDataEntry(value: valuesLineChart[0][i], xIndex: i))
      }
  }

And similarly with the other for loops