mathjs/lib/esm/function/set/setDistinct.js

import { flatten } from '../../utils/array.js';
import { factory } from '../../utils/factory.js';
var name = 'setDistinct';
var dependencies = ['typed', 'size', 'subset', 'compareNatural', 'Index', 'DenseMatrix'];
export var createSetDistinct = /* #__PURE__ */factory(name, dependencies, (_ref) => {
  var {
    typed,
    size,
    subset,
    compareNatural,
    Index,
    DenseMatrix
  } = _ref;

  /**
   * Collect the distinct elements of a multiset.
   * A multi-dimension array will be converted to a single-dimension array before the operation.
   *
   * Syntax:
   *
   *    math.setDistinct(set)
   *
   * Examples:
   *
   *    math.setDistinct([1, 1, 1, 2, 2, 3])        // returns [1, 2, 3]
   *
   * See also:
   *
   *    setMultiplicity
   *
   * @param {Array | Matrix}    a  A multiset
   * @return {Array | Matrix}    A set containing the distinc elements of the multiset
   */
  return typed(name, {
    'Array | Matrix': function ArrayMatrix(a) {
      var result;

      if (subset(size(a), new Index(0)) === 0) {
        // if empty, return empty
        result = [];
      } else {
        var b = flatten(Array.isArray(a) ? a : a.toArray()).sort(compareNatural);
        result = [];
        result.push(b[0]);

        for (var i = 1; i < b.length; i++) {
          if (compareNatural(b[i], b[i - 1]) !== 0) {
            result.push(b[i]);
          }
        }
      } // return an array, if the input was an array


      if (Array.isArray(a)) {
        return result;
      } // return a matrix otherwise


      return new DenseMatrix(result);
    }
  });
});