export class Lab1Component implements OnInit {

  public array: number[] = [2, 4, 4, 4.1, 5, 5, 5.5, 6, 7, 7.5, 7.5, 8, 8, 8, 8];
  public element: number;
  public invalidInput = false;
  public values = {
    'average': 0,
    'moda': 0,
    'median': 0,
    'dispersion': 0,
    'squareDeviation': 0,
    'area': 0,
    'fixedDispersion': 0,
    'fixedSquareDeviation': 0,
    'asymmetry': 0,
    'exses': 0
  };

  constructor() {
  }

  ngOnInit() {
    console.log(this.array);
    this.calculate();
  }

  addElement() {
    if (!isNullOrUndefined(this.element)) {
      this.array.push(this.element);
      this.invalidInput = false;
      this.element = null;
      this.calculate();
    } else {
      this.invalidInput = true;
    }
  }

  clear() {
    this.array = [];
  }

  calculate() {
    const sorted = this.array.sort((a, b) => a - b);
    this.values.average = this.array.reduce((previousValue, currentValue) => previousValue + currentValue) / this.array.length;
    this.values.moda = this.array.reduce((a, b, i, arr) =>
      (arr.filter(v => v === a).length >= arr.filter(v => v === b).length ? a : b), null);
    if (this.array.length % 2 === 0) {
      this.values.median = (this.array[this.array.length / 2] + this.array[this.array.length / 2 - 1]) / 2;
    } else {
      this.values.median = this.array[(this.array.length - 1) / 2];
    }
    const occurency = this.array.reduce(function (acc, curr) {
      if (typeof acc[curr] === 'undefined') {
        acc[curr] = 1;
      } else {
        acc[curr] += 1;
      }
      return acc;
    }, {});
    console.log(occurency);
    const set = Array.from(new Set(this.array));
    this.values.dispersion = ( set.map(value => Math.pow(value, 2) * occurency[value])
        .reduce((previousValue, currentValue) => previousValue + currentValue) / this.array.length )
      - Math.pow(this.values.average, 2);
    this.values.fixedDispersion = this.array.length / ( this.array.length - 1 ) * this.values.dispersion;
    this.values.squareDeviation = Math.sqrt(this.values.dispersion);
    this.values.fixedSquareDeviation = Math.sqrt(this.values.fixedDispersion);
    this.values.area = sorted[sorted.length - 1] - sorted[0];

    this.values.asymmetry = 1 / this.array.length * set.map(value => Math.pow(value - this.values.average, 3) * occurency[value])
      .reduce((previousValue, currentValue) => previousValue + currentValue) /
      Math.pow(this.values.squareDeviation, 3);
    this.values.exses = 1 / this.array.length * set.map(value => Math.pow(value - this.values.average, 4) * occurency[value])
        .reduce((previousValue, currentValue) => previousValue + currentValue) /
      Math.pow(this.values.squareDeviation, 4);
  }


}