| Yingyi Bu | e3d0ecd | 2016-02-24 10:56:59 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one |
| 3 | * or more contributor license agreements. See the NOTICE file |
| 4 | * distributed with this work for additional information |
| 5 | * regarding copyright ownership. The ASF licenses this file |
| 6 | * to you under the Apache License, Version 2.0 (the |
| 7 | * "License"); you may not use this file except in compliance |
| 8 | * with the License. You may obtain a copy of the License at |
| 9 | * |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 11 | * |
| 12 | * Unless required by applicable law or agreed to in writing, |
| 13 | * software distributed under the License is distributed on an |
| 14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| 15 | * KIND, either express or implied. See the License for the |
| 16 | * specific language governing permissions and limitations |
| 17 | * under the License. |
| 18 | */ |
| 19 | |
| 20 | declare function median($x) |
| 21 | { |
| 22 | let $c := count($x) |
| 23 | return avg( |
| 24 | for $i at $p in (for $j in $x order by $j return $j) |
| 25 | where $p >= floor(($c-1)/2.0) and $p <= $c/2 |
| 26 | return $i |
| 27 | ) |
| 28 | } |
| 29 | |
| 30 | |
| 31 | declare function MAD($x) |
| 32 | { |
| 33 | let $m := median($x) |
| 34 | return median(for $j in $x order by abs($j-$m) return abs($j-$m)) |
| 35 | } |
| 36 | |
| 37 | MAD([2, 3, 4, 1, 5, 6, 10, 0]) |
| 38 | |