visualizer / vendor / phpoffice / phpspreadsheet / src / PhpSpreadsheet / Shared / Trend / Trend.php

Trend.php in Visualizer – Tables & Charts Manager with Built-in AI Generator 3.9.4, at vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Shared/Trend/Trend.php

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1	<?php
2
3	namespace PhpOffice\PhpSpreadsheet\Shared\Trend;
4
5	class Trend
6	{
7	const TREND_LINEAR = 'Linear';
8	const TREND_LOGARITHMIC = 'Logarithmic';
9	const TREND_EXPONENTIAL = 'Exponential';
10	const TREND_POWER = 'Power';
11	const TREND_POLYNOMIAL_2 = 'Polynomial_2';
12	const TREND_POLYNOMIAL_3 = 'Polynomial_3';
13	const TREND_POLYNOMIAL_4 = 'Polynomial_4';
14	const TREND_POLYNOMIAL_5 = 'Polynomial_5';
15	const TREND_POLYNOMIAL_6 = 'Polynomial_6';
16	const TREND_BEST_FIT = 'Bestfit';
17	const TREND_BEST_FIT_NO_POLY = 'Bestfit_no_Polynomials';
18
19	/**
20	* Names of the best-fit Trend analysis methods.
21	*
22	* @var string[]
23	*/
24	private static $trendTypes = [
25	self::TREND_LINEAR,
26	self::TREND_LOGARITHMIC,
27	self::TREND_EXPONENTIAL,
28	self::TREND_POWER,
29	];
30
31	/**
32	* Names of the best-fit Trend polynomial orders.
33	*
34	* @var string[]
35	*/
36	private static $trendTypePolynomialOrders = [
37	self::TREND_POLYNOMIAL_2,
38	self::TREND_POLYNOMIAL_3,
39	self::TREND_POLYNOMIAL_4,
40	self::TREND_POLYNOMIAL_5,
41	self::TREND_POLYNOMIAL_6,
42	];
43
44	/**
45	* Cached results for each method when trying to identify which provides the best fit.
46	*
47	* @var bestFit[]
48	*/
49	private static $trendCache = [];
50
51	public static function calculate($trendType = self::TREND_BEST_FIT, $yValues = [], $xValues = [], $const = true)
52	{
53	// Calculate number of points in each dataset
54	$nY = count($yValues);
55	$nX = count($xValues);
56
57	// Define X Values if necessary
58	if ($nX == 0) {
59	$xValues = range(1, $nY);
60	$nX = $nY;
61	} elseif ($nY != $nX) {
62	// Ensure both arrays of points are the same size
63	trigger_error('Trend(): Number of elements in coordinate arrays do not match.', E_USER_ERROR);
64	}
65
66	$key = md5($trendType . $const . serialize($yValues) . serialize($xValues));
67	// Determine which Trend method has been requested
68	switch ($trendType) {
69	// Instantiate and return the class for the requested Trend method
70	case self::TREND_LINEAR:
71	case self::TREND_LOGARITHMIC:
72	case self::TREND_EXPONENTIAL:
73	case self::TREND_POWER:
74	if (!isset(self::$trendCache[$key])) {
75	$className = '\PhpOffice\PhpSpreadsheet\Shared\Trend\\' . $trendType . 'BestFit';
76	self::$trendCache[$key] = new $className($yValues, $xValues, $const);
77	}
78
79	return self::$trendCache[$key];
80	case self::TREND_POLYNOMIAL_2:
81	case self::TREND_POLYNOMIAL_3:
82	case self::TREND_POLYNOMIAL_4:
83	case self::TREND_POLYNOMIAL_5:
84	case self::TREND_POLYNOMIAL_6:
85	if (!isset(self::$trendCache[$key])) {
86	$order = substr($trendType, -1);
87	self::$trendCache[$key] = new PolynomialBestFit($order, $yValues, $xValues, $const);
88	}
89
90	return self::$trendCache[$key];
91	case self::TREND_BEST_FIT:
92	case self::TREND_BEST_FIT_NO_POLY:
93	// If the request is to determine the best fit regression, then we test each Trend line in turn
94	// Start by generating an instance of each available Trend method
95	foreach (self::$trendTypes as $trendMethod) {
96	$className = '\PhpOffice\PhpSpreadsheet\Shared\Trend\\' . $trendType . 'BestFit';
97	$bestFit[$trendMethod] = new $className($yValues, $xValues, $const);
98	$bestFitValue[$trendMethod] = $bestFit[$trendMethod]->getGoodnessOfFit();
99	}
100	if ($trendType != self::TREND_BEST_FIT_NO_POLY) {
101	foreach (self::$trendTypePolynomialOrders as $trendMethod) {
102	$order = substr($trendMethod, -1);
103	$bestFit[$trendMethod] = new PolynomialBestFit($order, $yValues, $xValues, $const);
104	if ($bestFit[$trendMethod]->getError()) {
105	unset($bestFit[$trendMethod]);
106	} else {
107	$bestFitValue[$trendMethod] = $bestFit[$trendMethod]->getGoodnessOfFit();
108	}
109	}
110	}
111	// Determine which of our Trend lines is the best fit, and then we return the instance of that Trend class
112	arsort($bestFitValue);
113	$bestFitType = key($bestFitValue);
114
115	return $bestFit[$bestFitType];
116	default:
117	return false;
118	}
119	}
120	}
121