simple-squiggle

A restricted subset of Squiggle
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mad.js (1850B)

      1 import { flatten } from '../../utils/array.js';
      2 import { factory } from '../../utils/factory.js';
      3 import { improveErrorMessage } from './utils/improveErrorMessage.js';
      4 var name = 'mad';
      5 var dependencies = ['typed', 'abs', 'map', 'median', 'subtract'];
      6 export var createMad = /* #__PURE__ */factory(name, dependencies, _ref => {
      7   var {
      8     typed,
      9     abs,
     10     map,
     11     median,
     12     subtract
     13   } = _ref;
     14 
     15   /**
     16    * Compute the median absolute deviation of a matrix or a list with values.
     17    * The median absolute deviation is defined as the median of the absolute
     18    * deviations from the median.
     19    *
     20    * Syntax:
     21    *
     22    *     math.mad(a, b, c, ...)
     23    *     math.mad(A)
     24    *
     25    * Examples:
     26    *
     27    *     math.mad(10, 20, 30)             // returns 10
     28    *     math.mad([1, 2, 3])              // returns 1
     29    *     math.mad([[1, 2, 3], [4, 5, 6]]) // returns 1.5
     30    *
     31    * See also:
     32    *
     33    *     median, mean, std, abs
     34    *
     35    * @param {Array | Matrix} array
     36    *                        A single matrix or multiple scalar values.
     37    * @return {*} The median absolute deviation.
     38    */
     39   return typed(name, {
     40     // mad([a, b, c, d, ...])
     41     'Array | Matrix': _mad,
     42     // mad(a, b, c, d, ...)
     43     '...': function _(args) {
     44       return _mad(args);
     45     }
     46   });
     47 
     48   function _mad(array) {
     49     array = flatten(array.valueOf());
     50 
     51     if (array.length === 0) {
     52       throw new Error('Cannot calculate median absolute deviation (mad) of an empty array');
     53     }
     54 
     55     try {
     56       var med = median(array);
     57       return median(map(array, function (value) {
     58         return abs(subtract(value, med));
     59       }));
     60     } catch (err) {
     61       if (err instanceof TypeError && err.message.indexOf('median') !== -1) {
     62         throw new TypeError(err.message.replace('median', 'mad'));
     63       } else {
     64         throw improveErrorMessage(err, 'mad');
     65       }
     66     }
     67   }
     68 });