simple-squiggle

A restricted subset of Squiggle
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setIntersect.js (2167B)

      1 import { flatten, generalize, identify } from '../../utils/array.js';
      2 import { factory } from '../../utils/factory.js';
      3 var name = 'setIntersect';
      4 var dependencies = ['typed', 'size', 'subset', 'compareNatural', 'Index', 'DenseMatrix'];
      5 export var createSetIntersect = /* #__PURE__ */factory(name, dependencies, _ref => {
      6   var {
      7     typed,
      8     size,
      9     subset,
     10     compareNatural,
     11     Index,
     12     DenseMatrix
     13   } = _ref;
     14 
     15   /**
     16    * Create the intersection of two (multi)sets.
     17    * Multi-dimension arrays will be converted to single-dimension arrays before the operation.
     18    *
     19    * Syntax:
     20    *
     21    *    math.setIntersect(set1, set2)
     22    *
     23    * Examples:
     24    *
     25    *    math.setIntersect([1, 2, 3, 4], [3, 4, 5, 6])            // returns [3, 4]
     26    *    math.setIntersect([[1, 2], [3, 4]], [[3, 4], [5, 6]])    // returns [3, 4]
     27    *
     28    * See also:
     29    *
     30    *    setUnion, setDifference
     31    *
     32    * @param {Array | Matrix}    a1  A (multi)set
     33    * @param {Array | Matrix}    a2  A (multi)set
     34    * @return {Array | Matrix}    The intersection of two (multi)sets
     35    */
     36   return typed(name, {
     37     'Array | Matrix, Array | Matrix': function ArrayMatrixArrayMatrix(a1, a2) {
     38       var result;
     39 
     40       if (subset(size(a1), new Index(0)) === 0 || subset(size(a2), new Index(0)) === 0) {
     41         // of any of them is empty, return empty
     42         result = [];
     43       } else {
     44         var b1 = identify(flatten(Array.isArray(a1) ? a1 : a1.toArray()).sort(compareNatural));
     45         var b2 = identify(flatten(Array.isArray(a2) ? a2 : a2.toArray()).sort(compareNatural));
     46         result = [];
     47 
     48         for (var i = 0; i < b1.length; i++) {
     49           for (var j = 0; j < b2.length; j++) {
     50             if (compareNatural(b1[i].value, b2[j].value) === 0 && b1[i].identifier === b2[j].identifier) {
     51               // the identifier is always a decimal int
     52               result.push(b1[i]);
     53               break;
     54             }
     55           }
     56         }
     57       } // return an array, if both inputs were arrays
     58 
     59 
     60       if (Array.isArray(a1) && Array.isArray(a2)) {
     61         return generalize(result);
     62       } // return a matrix otherwise
     63 
     64 
     65       return new DenseMatrix(generalize(result));
     66     }
     67   });
     68 });