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<?php |
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/** |
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* This file is part of PHP K-Means |
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* |
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* Copyright (c) 2014 Benjamin Delespierre |
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* |
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* Permission is hereby granted, free of charge, to any person obtaining a copy |
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* of this software and associated documentation files (the "Software"), to deal |
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* in the Software without restriction, including without limitation the rights |
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
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* copies of the Software, and to permit persons to whom the Software is furnished |
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* to do so, subject to the following conditions: |
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* |
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* The above copyright notice and this permission notice shall be included in all |
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* copies or substantial portions of the Software. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
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* THE SOFTWARE. |
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*/ |
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namespace KMeans; |
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class Point implements \ArrayAccess |
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{ |
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protected $space; |
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protected $dimention; |
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protected $coordinates; |
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public function __construct(Space $space, array $coordinates) |
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{ |
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$this->space = $space; |
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$this->dimention = $space->getDimention(); |
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$this->coordinates = $coordinates; |
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} |
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public function toArray(): array |
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{ |
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return [ |
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'coordinates' => $this->coordinates, |
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'data' => isset($this->space[$this]) ? $this->space[$this] : null, |
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]; |
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} |
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public function getDistanceWith(self $point, bool $precise = true): float |
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{ |
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if ($point->space !== $this->space) { |
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throw new \LogicException("can only calculate distances from points in the same space"); |
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} |
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$distance = 0; |
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for ($n = 0; $n < $this->dimention; $n++) { |
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$difference = $this->coordinates[$n] - $point->coordinates[$n]; |
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$distance += $difference * $difference; |
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} |
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return $precise ? sqrt($distance) : $distance; |
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} |
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public function getClosest(iterable $points): Point |
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{ |
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foreach ($points as $point) { |
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$distance = $this->getDistanceWith($point, false); |
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if (!isset($minDistance)) { |
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$minDistance = $distance; |
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$minPoint = $point; |
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continue; |
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} |
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if ($distance < $minDistance) { |
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$minDistance = $distance; |
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$minPoint = $point; |
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} |
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} |
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return $minPoint; |
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} |
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public function belongsTo(Space $space): bool |
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{ |
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return $this->space === $space; |
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} |
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public function getSpace(): Space |
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{ |
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return $this->space; |
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} |
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public function getCoordinates(): array |
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{ |
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return $this->coordinates; |
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} |
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public function offsetExists($offset): bool |
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{ |
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return isset($this->coordinates[$offset]); |
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} |
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public function offsetGet($offset) |
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{ |
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return $this->coordinates[$offset]; |
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} |
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public function offsetSet($offset, $value): void |
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{ |
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$this->coordinates[$offset] = $value; |
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} |
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public function offsetUnset($offset): void |
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{ |
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unset($this->coordinates[$offset]); |
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} |
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} |
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If you define a variable conditionally, it can happen that it is not defined for all execution paths.
Let’s take a look at an example:
In the above example, the variable $x is defined if you pass “foo” or “bar” as argument for $a. However, since the switch statement has no default case statement, if you pass any other value, the variable $x would be undefined.
Available Fixes
Check for existence of the variable explicitly:
Define a default value for the variable:
Add a value for the missing path: