tablepress / libraries / vendor / PhpSpreadsheet / Calculation / Statistical / Distributions / Fisher.php

Fisher.php in TablePress – Tables in WordPress made easy 3.4, at libraries/vendor/PhpSpreadsheet/Calculation/Statistical/Distributions/Fisher.php

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1	<?php
2
3	namespace TablePress\PhpOffice\PhpSpreadsheet\Calculation\Statistical\Distributions;
4
5	use TablePress\PhpOffice\PhpSpreadsheet\Calculation\ArrayEnabled;
6	use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Exception;
7	use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Information\ExcelError;
8
9	class Fisher
10	{
11	use ArrayEnabled;
12
13	/**
14	* FISHER.
15	*
16	* Returns the Fisher transformation at x. This transformation produces a function that
17	* is normally distributed rather than skewed. Use this function to perform hypothesis
18	* testing on the correlation coefficient.
19	*
20	* @param mixed $value Float value for which we want the probability
21	* Or can be an array of values
22	*
23	* @return array<mixed>\|float\|string If an array of numbers is passed as an argument, then the returned result will also be an array
24	* with the same dimensions
25	*/
26	public static function distribution($value)
27	{
28	if (is_array($value)) {
29	return self::evaluateSingleArgumentArray([self::class, __FUNCTION__], $value);
30	}
31
32	try {
33	$value = DistributionValidations::validateFloat($value);
34	} catch (Exception $e) {
35	return $e->getMessage();
36	}
37
38	if (($value <= -1) \|\| ($value >= 1)) {
39	return ExcelError::NAN();
40	}
41
42	return 0.5 * log((1 + $value) / (1 - $value));
43	}
44
45	/**
46	* FISHERINV.
47	*
48	* Returns the inverse of the Fisher transformation. Use this transformation when
49	* analyzing correlations between ranges or arrays of data. If y = FISHER(x), then
50	* FISHERINV(y) = x.
51	*
52	* @param mixed $probability Float probability at which you want to evaluate the distribution
53	* Or can be an array of values
54	*
55	* @return array<mixed>\|float\|string If an array of numbers is passed as an argument, then the returned result will also be an array
56	* with the same dimensions
57	*/
58	public static function inverse($probability)
59	{
60	if (is_array($probability)) {
61	return self::evaluateSingleArgumentArray([self::class, __FUNCTION__], $probability);
62	}
63
64	try {
65	$probability = DistributionValidations::validateFloat($probability);
66	} catch (Exception $e) {
67	return $e->getMessage();
68	}
69
70	return (exp(2 * $probability) - 1) / (exp(2 * $probability) + 1);
71	}
72	}
73