simple-squiggle/node_modules/mathjs/lib/esm/function/statistics/median.js

111 lines
3.3 KiB
JavaScript

import { containsCollections } from '../../utils/collection.js';
import { flatten } from '../../utils/array.js';
import { factory } from '../../utils/factory.js';
import { improveErrorMessage } from './utils/improveErrorMessage.js';
var name = 'median';
var dependencies = ['typed', 'add', 'divide', 'compare', 'partitionSelect'];
export var createMedian = /* #__PURE__ */factory(name, dependencies, _ref => {
var {
typed,
add,
divide,
compare,
partitionSelect
} = _ref;
/**
* Recursively calculate the median of an n-dimensional array
* @param {Array} array
* @return {Number} median
* @private
*/
function _median(array) {
try {
array = flatten(array.valueOf());
var num = array.length;
if (num === 0) {
throw new Error('Cannot calculate median of an empty array');
}
if (num % 2 === 0) {
// even: return the average of the two middle values
var mid = num / 2 - 1;
var right = partitionSelect(array, mid + 1); // array now partitioned at mid + 1, take max of left part
var left = array[mid];
for (var i = 0; i < mid; ++i) {
if (compare(array[i], left) > 0) {
left = array[i];
}
}
return middle2(left, right);
} else {
// odd: return the middle value
var m = partitionSelect(array, (num - 1) / 2);
return middle(m);
}
} catch (err) {
throw improveErrorMessage(err, 'median');
}
} // helper function to type check the middle value of the array
var middle = typed({
'number | BigNumber | Complex | Unit': function numberBigNumberComplexUnit(value) {
return value;
}
}); // helper function to type check the two middle value of the array
var middle2 = typed({
'number | BigNumber | Complex | Unit, number | BigNumber | Complex | Unit': function numberBigNumberComplexUnitNumberBigNumberComplexUnit(left, right) {
return divide(add(left, right), 2);
}
});
/**
* Compute the median of a matrix or a list with values. The values are
* sorted and the middle value is returned. In case of an even number of
* values, the average of the two middle values is returned.
* Supported types of values are: Number, BigNumber, Unit
*
* In case of a (multi dimensional) array or matrix, the median of all
* elements will be calculated.
*
* Syntax:
*
* math.median(a, b, c, ...)
* math.median(A)
*
* Examples:
*
* math.median(5, 2, 7) // returns 5
* math.median([3, -1, 5, 7]) // returns 4
*
* See also:
*
* mean, min, max, sum, prod, std, variance, quantileSeq
*
* @param {... *} args A single matrix or or multiple scalar values
* @return {*} The median
*/
return typed(name, {
// median([a, b, c, d, ...])
'Array | Matrix': _median,
// median([a, b, c, d, ...], dim)
'Array | Matrix, number | BigNumber': function ArrayMatrixNumberBigNumber(array, dim) {
// TODO: implement median(A, dim)
throw new Error('median(A, dim) is not yet supported'); // return reduce(arguments[0], arguments[1], ...)
},
// median(a, b, c, d, ...)
'...': function _(args) {
if (containsCollections(args)) {
throw new TypeError('Scalar values expected in function median');
}
return _median(args);
}
});
});