CART::grow() - Code Metrics - Inspection of "Implement DecisionTreeRegressor (#375)" - php-ai/php-ml - Measure and Improve Code Quality continuously with Scrutinizer

Test Setup Failed

Push — master ( 8544cf...91812f )

by Arkadiusz

created 2019-05-12 18:04 UTC

CART::grow() B

↳ Parent: CART

Complexity

Conditions	9
Paths	12

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
dl	0
loc	61
rs	7.2953
c	0
b	0
f	0
cc	9
nc	12
nop	2

How to fix Long Method

<?php

declare(strict_types=1);

namespace Phpml\Tree;

use Phpml\Exception\InvalidArgumentException;
use Phpml\Tree\Node\BinaryNode;
use Phpml\Tree\Node\DecisionNode;
use Phpml\Tree\Node\LeafNode;

abstract class CART
{
    /**
     * @var DecisionNode|null
     */
    protected $root;

    /**
     * @var int
     */
    protected $maxDepth;

    /**
     * @var int
     */
    protected $maxLeafSize;

    /**
     * @var float
     */
    protected $minPurityIncrease;

    /**
     * @var int
     */
    protected $featureCount;

    public function __construct(int $maxDepth = PHP_INT_MAX, int $maxLeafSize = 3, float $minPurityIncrease = 0.)
    {
        if ($maxDepth < 1) {
            throw new InvalidArgumentException('Max depth must be greater than 0');
        }

        if ($maxLeafSize < 1) {
            throw new InvalidArgumentException('Max leaf size must be greater than 0');
        }

        if ($minPurityIncrease < 0.) {
            throw new InvalidArgumentException('Min purity increase must be equal or greater than 0');
        }

        $this->maxDepth = $maxDepth;
        $this->maxLeafSize = $maxLeafSize;
        $this->minPurityIncrease = $minPurityIncrease;
    }

    public function root(): ?DecisionNode
    {
        return $this->root;
    }

    public function height(): int
    {
        return $this->root !== null ? $this->root->height() : 0;
    }

    public function balance(): int
    {
        return $this->root !== null ? $this->root->balance() : 0;
    }

    public function bare(): bool
    {
        return $this->root === null;
    }

    public function grow(array $samples, array $targets): void
    {
        $this->featureCount = count($samples[0]);
        $depth = 1;
        $this->root = $this->split($samples, $targets);
        $stack = [[$this->root, $depth]];

        while ($stack) {

            [$current, $depth] = array_pop($stack) ?? [];


            [$left, $right] = $current->groups();


            $current->cleanup();

            $depth++;

            if ($left === [] || $right === []) {
                $node = $this->terminate(array_merge($left[1], $right[1]));

                $current->attachLeft($node);
                $current->attachRight($node);

                continue 1;
            }

            if ($depth >= $this->maxDepth) {
                $current->attachLeft($this->terminate($left[1]));
                $current->attachRight($this->terminate($right[1]));

                continue 1;
            }

            if (count($left[1]) > $this->maxLeafSize) {
                $node = $this->split($left[0], $left[1]);

                if ($node->purityIncrease() + 1e-8 > $this->minPurityIncrease) {
                    $current->attachLeft($node);

                    $stack[] = [$node, $depth];
                } else {
                    $current->attachLeft($this->terminate($left[1]));
                }
            } else {
                $current->attachLeft($this->terminate($left[1]));
            }

            if (count($right[1]) > $this->maxLeafSize) {
                $node = $this->split($right[0], $right[1]);

                if ($node->purityIncrease() + 1e-8 > $this->minPurityIncrease) {
                    $current->attachRight($node);

                    $stack[] = [$node, $depth];
                } else {
                    $current->attachRight($this->terminate($right[1]));
                }
            } else {
                $current->attachRight($this->terminate($right[1]));
            }
        }
    }

    public function search(array $sample): ?BinaryNode
    {
        $current = $this->root;

        while ($current) {
            if ($current instanceof DecisionNode) {
                $value = $current->value();

                if (is_string($value)) {
                    if ($sample[$current->column()] === $value) {
                        $current = $current->left();
                    } else {
                        $current = $current->right();
                    }
                } else {
                    if ($sample[$current->column()] < $value) {
                        $current = $current->left();
                    } else {
                        $current = $current->right();
                    }
                }

                continue 1;
            }

            if ($current instanceof LeafNode) {
                break 1;
            }
        }

        return $current;
    }

    abstract protected function split(array $samples, array $targets): DecisionNode;

    abstract protected function terminate(array $targets): BinaryNode;
}


1			<?php
2
3			declare(strict_types=1);
4
5			namespace Phpml\Tree;
6
7			use Phpml\Exception\InvalidArgumentException;
8			use Phpml\Tree\Node\BinaryNode;
9			use Phpml\Tree\Node\DecisionNode;
10			use Phpml\Tree\Node\LeafNode;
11
12			abstract class CART
13			{
14			/**
15			* @var DecisionNode\|null
16			*/
17			protected $root;
18
19			/**
20			* @var int
21			*/
22			protected $maxDepth;
23
24			/**
25			* @var int
26			*/
27			protected $maxLeafSize;
28
29			/**
30			* @var float
31			*/
32			protected $minPurityIncrease;
33
34			/**
35			* @var int
36			*/
37			protected $featureCount;
38
39			public function __construct(int $maxDepth = PHP_INT_MAX, int $maxLeafSize = 3, float $minPurityIncrease = 0.)
40			{
41			if ($maxDepth < 1) {
42			throw new InvalidArgumentException('Max depth must be greater than 0');
43			}
44
45			if ($maxLeafSize < 1) {
46			throw new InvalidArgumentException('Max leaf size must be greater than 0');
47			}
48
49			if ($minPurityIncrease < 0.) {
50			throw new InvalidArgumentException('Min purity increase must be equal or greater than 0');
51			}
52
53			$this->maxDepth = $maxDepth;
54			$this->maxLeafSize = $maxLeafSize;
55			$this->minPurityIncrease = $minPurityIncrease;
56			}
57
58			public function root(): ?DecisionNode
59			{
60			return $this->root;
61			}
62
63			public function height(): int
64			{
65			return $this->root !== null ? $this->root->height() : 0;
66			}
67
68			public function balance(): int
69			{
70			return $this->root !== null ? $this->root->balance() : 0;
71			}
72
73			public function bare(): bool
74			{
75			return $this->root === null;
76			}
77
78			public function grow(array $samples, array $targets): void
79			{
80			$this->featureCount = count($samples[0]);
81			$depth = 1;
82			$this->root = $this->split($samples, $targets);
83			$stack = [[$this->root, $depth]];
84
85			while ($stack) {
			0 ignored issues – show Bug Best Practice introduced 2019-05-12 18:03 UTC by Report Bug Copy Issue Report The expression `$stack` of type `array` is implicitly converted to a boolean; are you sure this is intended? If so, consider using `! empty($expr)` instead to make it clear that you intend to check for an array without elements. This check marks implicit conversions of arrays to boolean values in a comparison. While in PHP an empty array is considered to be equal (but not identical) to false, this is not always apparent. Consider making the comparison explicit by using `empty(..)` or `! empty(...)` instead. Loading history...
86			[$current, $depth] = array_pop($stack) ?? [];
			0 ignored issues – show Bug introduced 2019-05-12 18:03 UTC by Report Bug Copy Issue Report The variable `$current` does not exist. Did you forget to declare it? This check marks access to variables or properties that have not been declared yet. While PHP has no explicit notion of declaring a variable, accessing it before a value is assigned to it is most likely a bug. Loading history...
87
88			[$left, $right] = $current->groups();
			0 ignored issues – show Bug introduced 2019-05-12 18:03 UTC by Report Bug Copy Issue Report The variable `$left` does not exist. Did you forget to declare it? This check marks access to variables or properties that have not been declared yet. While PHP has no explicit notion of declaring a variable, accessing it before a value is assigned to it is most likely a bug. Loading history... Bug introduced 2019-05-12 18:03 UTC by Report Bug Copy Issue Report The variable `$right` does not exist. Did you forget to declare it? This check marks access to variables or properties that have not been declared yet. While PHP has no explicit notion of declaring a variable, accessing it before a value is assigned to it is most likely a bug. Loading history...
89
90			$current->cleanup();
91
92			$depth++;
93
94			if ($left === [] \|\| $right === []) {
95			$node = $this->terminate(array_merge($left[1], $right[1]));
96
97			$current->attachLeft($node);
98			$current->attachRight($node);
99
100			continue 1;
101			}
102
103			if ($depth >= $this->maxDepth) {
104			$current->attachLeft($this->terminate($left[1]));
105			$current->attachRight($this->terminate($right[1]));
106
107			continue 1;
108			}
109
110			if (count($left[1]) > $this->maxLeafSize) {
111			$node = $this->split($left[0], $left[1]);
112
113			if ($node->purityIncrease() + 1e-8 > $this->minPurityIncrease) {
114			$current->attachLeft($node);
115
116			$stack[] = [$node, $depth];
117			} else {
118			$current->attachLeft($this->terminate($left[1]));
119			}
120			} else {
121			$current->attachLeft($this->terminate($left[1]));
122			}
123
124			if (count($right[1]) > $this->maxLeafSize) {
125			$node = $this->split($right[0], $right[1]);
126
127			if ($node->purityIncrease() + 1e-8 > $this->minPurityIncrease) {
128			$current->attachRight($node);
129
130			$stack[] = [$node, $depth];
131			} else {
132			$current->attachRight($this->terminate($right[1]));
133			}
134			} else {
135			$current->attachRight($this->terminate($right[1]));
136			}
137			}
138			}
139
140			public function search(array $sample): ?BinaryNode
141			{
142			$current = $this->root;
143
144			while ($current) {
145			if ($current instanceof DecisionNode) {
146			$value = $current->value();
147
148			if (is_string($value)) {
149			if ($sample[$current->column()] === $value) {
150			$current = $current->left();
151			} else {
152			$current = $current->right();
153			}
154			} else {
155			if ($sample[$current->column()] < $value) {
156			$current = $current->left();
157			} else {
158			$current = $current->right();
159			}
160			}
161
162			continue 1;
163			}
164
165			if ($current instanceof LeafNode) {
166			break 1;
167			}
168			}
169
170			return $current;
171			}
172
173			abstract protected function split(array $samples, array $targets): DecisionNode;
174
175			abstract protected function terminate(array $targets): BinaryNode;
176			}
177

php-ai / php-ml

Push — master ( 8544cf...91812f )

CART::grow() B

Complexity

Size

Duplication

Importance

How to fix Long Method

Long Method

Duplication Side-by-Side

Filter issues like