111 lines
3.3 KiB
JavaScript
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);
|
||
|
|
}
|
||
|
|
});
|
||
|
|
});
|