simple-squiggle

A restricted subset of Squiggle
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multinomial.js (1794B)

      1 "use strict";
      2 
      3 Object.defineProperty(exports, "__esModule", {
      4   value: true
      5 });
      6 exports.createMultinomial = void 0;
      7 
      8 var _collection = require("../../utils/collection.js");
      9 
     10 var _factory = require("../../utils/factory.js");
     11 
     12 var name = 'multinomial';
     13 var dependencies = ['typed', 'add', 'divide', 'multiply', 'factorial', 'isInteger', 'isPositive'];
     14 var createMultinomial = /* #__PURE__ */(0, _factory.factory)(name, dependencies, function (_ref) {
     15   var typed = _ref.typed,
     16       add = _ref.add,
     17       divide = _ref.divide,
     18       multiply = _ref.multiply,
     19       factorial = _ref.factorial,
     20       isInteger = _ref.isInteger,
     21       isPositive = _ref.isPositive;
     22 
     23   /**
     24    * Multinomial Coefficients compute the number of ways of picking a1, a2, ..., ai unordered outcomes from `n` possibilities.
     25    *
     26    * multinomial takes one array of integers as an argument.
     27    * The following condition must be enforced: every ai <= 0
     28    *
     29    * Syntax:
     30    *
     31    *     math.multinomial(a) // a is an array type
     32    *
     33    * Examples:
     34    *
     35    *    math.multinomial([1,2,1]) // returns 12
     36    *
     37    * See also:
     38    *
     39    *    combinations, factorial
     40    *
     41    * @param {number[] | BigNumber[]} a    Integer numbers of objects in the subset
     42    * @return {Number | BigNumber}         Multinomial coefficient.
     43    */
     44   return typed(name, {
     45     'Array | Matrix': function ArrayMatrix(a) {
     46       var sum = 0;
     47       var denom = 1;
     48       (0, _collection.deepForEach)(a, function (ai) {
     49         if (!isInteger(ai) || !isPositive(ai)) {
     50           throw new TypeError('Positive integer value expected in function multinomial');
     51         }
     52 
     53         sum = add(sum, ai);
     54         denom = multiply(denom, factorial(ai));
     55       });
     56       return divide(factorial(sum), denom);
     57     }
     58   });
     59 });
     60 exports.createMultinomial = createMultinomial;