SplineChart in flutter

Issue

I was trying to make a chart that can read values from a big List. I've got some help from @MiftakhulArzak " Line chart representation of List containing double values ", thanks to him. Anyway I tried to implement the suggested solution but It didnt completely work for me which I think because I messed up the code somehow.

 static List x =[26.0,13.10,1.3,1.5,1.9,1.8,1.9,2.9,3.0,1.9,1.8,1.4,9.0,2.0,3.4,4.7,1.8,1.9,2.9,3.0,1.9,1.8,1.4,1.0,2.0,3.4,4.7];

  @override
  Widget build(BuildContext context) {

    final List<ChartData> chartData = [
      ChartData(4, x),


    ];
    List<SplineSeries> generateSplineSeries(List<ChartData> chartData){

      List<SplineSeries> splines = [];
      for(int i=0; i<chartData.first.y!.length; i++){
        splines.add( SplineSeries<ChartData, int>(
          dataSource: chartData,
          xValueMapper: (ChartData data, _) => data.x,
          yValueMapper: (ChartData data, _) => data.y![i]
        ));
      }
      return splines;
    }
    return Scaffold(
        body: Center(
            child: Container(
                child: SfCartesianChart(
                    series: generateSplineSeries(chartData),
                )
            )
        )
    );
  }
}
class ChartData {
  ChartData(this.x, this.y);
  final int x;
  final List? y;
}

With this Code I get the outpus as this:

As you can see, No Line graph has been drawn. Can you point to me what am I doing wrong

Solution

Please update code with this,

static List<double> x =[26.0,13.10,1.3,1.5,1.9,1.8,1.9,2.9,3.0,1.9,1.8,1.4,9.0,2.0,3.4,4.7,1.8,1.9,2.9,3.0,1.9,1.8,1.4,1.0,2.0,3.4,4.7];
  @override
  Widget build(BuildContext context) {

    final List<ChartData> chartData = getItems(x);
    List<SplineSeries> generateSplineSeries(List<ChartData> chartData){

      List<SplineSeries> splines = [];
      for(int i=0; i<chartData.first.y!.length; i++){
        splines.add( SplineSeries<ChartData, int>(
            dataSource: chartData,
            xValueMapper: (ChartData data, _) => data.x,
            yValueMapper: (ChartData data, _) => data.y![i]
        ));
      }
      return splines;
    }
    return Scaffold(
        body: Center(
            child: Container(
                child: SfCartesianChart(
                  series: generateSplineSeries(chartData),
                )
            )
        )
    );
  }

  List<ChartData> getItems(List<double> x) {
    List<ChartData> items  = [];
    int currentValue = 10;
    for(int i = 0; i< x.length ; i++){
      items.add(ChartData(currentValue, [x[i]]));
      currentValue+=10;
    }
    return items;
  }

It will look like, I am not sure do you want to achieve this or else. If you want to achieve something different, please comment here.

Answered By - ABV