tablepress / libraries / vendor / PhpSpreadsheet / Calculation / Engineering / Erf.php

Erf.php in TablePress – Tables in WordPress made easy 3.4, at libraries/vendor/PhpSpreadsheet/Calculation/Engineering/Erf.php

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1	<?php
2
3	namespace TablePress\PhpOffice\PhpSpreadsheet\Calculation\Engineering;
4
5	use TablePress\PhpOffice\PhpSpreadsheet\Calculation\ArrayEnabled;
6	use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Functions;
7	use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Information\ExcelError;
8
9	class Erf
10	{
11	use ArrayEnabled;
12
13	private const TWO_SQRT_PI = 1.128379167095512574;
14
15	/**
16	* ERF.
17	*
18	* Returns the error function integrated between the lower and upper bound arguments.
19	*
20	* Note: In Excel 2007 or earlier, if you input a negative value for the upper or lower bound arguments,
21	* the function would return a #NUM! error. However, in Excel 2010, the function algorithm was
22	* improved, so that it can now calculate the function for both positive and negative ranges.
23	* PhpSpreadsheet follows Excel 2010 behaviour, and accepts negative arguments.
24	*
25	* Excel Function:
26	* ERF(lower[,upper])
27	*
28	* @param mixed $lower Lower bound float for integrating ERF
29	* Or can be an array of values
30	* @param mixed $upper Upper bound float for integrating ERF.
31	* If omitted, ERF integrates between zero and lower_limit
32	* Or can be an array of values
33	*
34	* @return array<mixed>\|float\|string If an array of numbers is passed as an argument, then the returned result will also be an array
35	* with the same dimensions
36	*/
37	public static function ERF($lower, $upper = null)
38	{
39	if (is_array($lower) \|\| is_array($upper)) {
40	return self::evaluateArrayArguments([self::class, __FUNCTION__], $lower, $upper);
41	}
42
43	if (is_numeric($lower)) {
44	if ($upper === null) {
45	return self::erfValue($lower);
46	}
47	if (is_numeric($upper)) {
48	return self::erfValue($upper) - self::erfValue($lower);
49	}
50	}
51
52	return ExcelError::VALUE();
53	}
54
55	/**
56	* ERFPRECISE.
57	*
58	* Returns the error function integrated between the lower and upper bound arguments.
59	*
60	* Excel Function:
61	* ERF.PRECISE(limit)
62	*
63	* @param mixed $limit Float bound for integrating ERF, other bound is zero
64	* Or can be an array of values
65	*
66	* @return array<mixed>\|float\|string If an array of numbers is passed as an argument, then the returned result will also be an array
67	* with the same dimensions
68	*/
69	public static function ERFPRECISE($limit)
70	{
71	if (is_array($limit)) {
72	return self::evaluateSingleArgumentArray([self::class, __FUNCTION__], $limit);
73	}
74
75	return self::ERF($limit);
76	}
77
78	/**
79	* @param mixed $value
80	*/
81	private static function makeFloat($value): float
82	{
83	return is_numeric($value) ? ((float) $value) : 0.0;
84	}
85
86	/**
87	* Method to calculate the erf value.
88	* @param float\|int\|string $value
89	*/
90	public static function erfValue($value): float
91	{
92	$value = (float) $value;
93	if (abs($value) > 2.2) {
94	return 1 - self::makeFloat(ErfC::ERFC($value));
95	}
96	$sum = $term = $value;
97	$xsqr = ($value * $value);
98	$j = 1;
99	do {
100	$term *= $xsqr / $j;
101	$sum -= $term / (2 * $j + 1);
102	++$j;
103	$term *= $xsqr / $j;
104	$sum += $term / (2 * $j + 1);
105	++$j;
106	if ($sum == 0.0) {
107	break;
108	}
109	} while (abs($term / $sum) > Functions::PRECISION);
110
111	return self::TWO_SQRT_PI * $sum;
112	}
113	}
114