Proyectos de Subversion Moodle

Rev

| Ultima modificación | Ver Log |

Rev Autor Línea Nro. Línea
1441 ariadna 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 array $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 array $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 array $trendCache = [];
50 
 
51 
    public static function calculate(string $trendType = self::TREND_BEST_FIT, array $yValues = [], array $xValues = [], bool $const = true): mixed
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, $nY);
60 
        } elseif ($nY !== $nX) {
61 
            //    Ensure both arrays of points are the same size
62 
            trigger_error('Trend(): Number of elements in coordinate arrays do not match.', E_USER_ERROR);
63 
        }
64 
 
65 
        $key = md5($trendType . $const . serialize($yValues) . serialize($xValues));
66 
        //    Determine which Trend method has been requested
67 
        switch ($trendType) {
68 
            //    Instantiate and return the class for the requested Trend method
69 
            case self::TREND_LINEAR:
70 
            case self::TREND_LOGARITHMIC:
71 
            case self::TREND_EXPONENTIAL:
72 
            case self::TREND_POWER:
73 
                if (!isset(self::$trendCache[$key])) {
74 
                    $className = '\PhpOffice\PhpSpreadsheet\Shared\Trend\\' . $trendType . 'BestFit';
75 
                    self::$trendCache[$key] = new $className($yValues, $xValues, $const);
76 
                }
77 
 
78 
                return self::$trendCache[$key];
79 
            case self::TREND_POLYNOMIAL_2:
80 
            case self::TREND_POLYNOMIAL_3:
81 
            case self::TREND_POLYNOMIAL_4:
82 
            case self::TREND_POLYNOMIAL_5:
83 
            case self::TREND_POLYNOMIAL_6:
84 
                if (!isset(self::$trendCache[$key])) {
85 
                    $order = (int) substr($trendType, -1);
86 
                    self::$trendCache[$key] = new PolynomialBestFit($order, $yValues, $xValues);
87 
                }
88 
 
89 
                return self::$trendCache[$key];
90 
            case self::TREND_BEST_FIT:
91 
            case self::TREND_BEST_FIT_NO_POLY:
92 
                //    If the request is to determine the best fit regression, then we test each Trend line in turn
93 
                //    Start by generating an instance of each available Trend method
94 
                $bestFit = [];
95 
                $bestFitValue = [];
96 
                foreach (self::$trendTypes as $trendMethod) {
97 
                    $className = '\PhpOffice\PhpSpreadsheet\Shared\Trend\\' . $trendType . 'BestFit';
98 
                    //* @phpstan-ignore-next-line
99 
                    $bestFit[$trendMethod] = new $className($yValues, $xValues, $const);
100 
                    $bestFitValue[$trendMethod] = $bestFit[$trendMethod]->getGoodnessOfFit();
101 
                }
102 
                if ($trendType != self::TREND_BEST_FIT_NO_POLY) {
103 
                    foreach (self::$trendTypePolynomialOrders as $trendMethod) {
104 
                        $order = (int) substr($trendMethod, -1);
105 
                        $bestFit[$trendMethod] = new PolynomialBestFit($order, $yValues, $xValues);
106 
                        if ($bestFit[$trendMethod]->getError()) {
107 
                            unset($bestFit[$trendMethod]);
108 
                        } else {
109 
                            $bestFitValue[$trendMethod] = $bestFit[$trendMethod]->getGoodnessOfFit();
110 
                        }
111 
                    }
112 
                }
113 
                //    Determine which of our Trend lines is the best fit, and then we return the instance of that Trend class
114 
                arsort($bestFitValue);
115 
                $bestFitType = key($bestFitValue);
116 
 
117 
                return $bestFit[$bestFitType];
118 
            default:
119 
                return false;
120 
        }
121 
    }
122 
}