Get Array of Values from a Nested Data

Question

guys. How to get values from an array of the nested object, which I getting from the parent component.

For example:

  @Input() result?: FullResult;

  constructor() {}

  ngOnInit(): void {
    Chart.register(...registerables);
    chart.default.createChart()
  }

  updateData() {
    
    const data = this.result?.threePhaseResult.chartSet;

    console.log(data). // Here I get the object, that consist two objects - Curve and EnvelopeCurve. Both objects include an array of coordinate.

    const time = data?.Curve.map(function(coordinate) { return coordinate.X});
    const K = data?.Curve.map(function(coordinate) { return coordinate.Y});
    const Kenv = data?.EnvelopeCurve.map(function(coordinate) { return coordinate.Y});

    this.chart.config.labels = time;
    this.chart.config.data.datasets[0].data = K;
    this.chart.config.data.datasets[0].data = Kenv;

    this.chart.update()
  }

  

I always get "TypeError: undefined is not an object (evaluating 'a.data.Curve.map')". Please help me to fix my mistake.