# tablepress/3.4/libraries/vendor/PhpSpreadsheet/Calculation/Statistical/Distributions/Gamma.php

TablePress – Tables in WordPress made easy, version 3.4. 156 lines.

- Page: https://pluginprobe.com/plugins/tablepress/3.4/code/libraries/vendor/PhpSpreadsheet/Calculation/Statistical/Distributions/Gamma.php
- Raw: https://pluginprobe.com/plugins/tablepress/3.4/raw/libraries/vendor/PhpSpreadsheet/Calculation/Statistical/Distributions/Gamma.php
- Modified: 2026-09-30T03:50:46+00:00

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```php
<?php

namespace TablePress\PhpOffice\PhpSpreadsheet\Calculation\Statistical\Distributions;

use TablePress\PhpOffice\PhpSpreadsheet\Calculation\ArrayEnabled;
use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Exception;
use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Information\ExcelError;

class Gamma extends GammaBase
{
	use ArrayEnabled;

	/**
	 * GAMMA.
	 *
	 * Return the gamma function value.
	 *
	 * @param mixed $value Float value for which we want the probability
	 *                      Or can be an array of values
	 *
	 * @return array<mixed>|float|string The result, or a string containing an error
	 *         If an array of numbers is passed as an argument, then the returned result will also be an array
	 *            with the same dimensions
	 */
	public static function gamma($value)
	{
		if (is_array($value)) {
			return self::evaluateSingleArgumentArray([self::class, __FUNCTION__], $value);
		}

		try {
			$value = DistributionValidations::validateFloat($value);
		} catch (Exception $e) {
			return $e->getMessage();
		}

		if ((((int) $value) == ((float) $value)) && $value <= 0.0) {
			return ExcelError::NAN();
		}

		return self::gammaValue($value);
	}

	/**
	 * GAMMADIST.
	 *
	 * Returns the gamma distribution.
	 *
	 * @param mixed $value Float Value at which you want to evaluate the distribution
	 *                      Or can be an array of values
	 * @param mixed $a Parameter to the distribution as a float
	 *                      Or can be an array of values
	 * @param mixed $b Parameter to the distribution as a float
	 *                      Or can be an array of values
	 * @param mixed $cumulative Boolean value indicating if we want the cdf (true) or the pdf (false)
	 *                      Or can be an array of values
	 *
	 * @return array<mixed>|float|string If an array of numbers is passed as an argument, then the returned result will also be an array
	 *            with the same dimensions
	 */
	public static function distribution($value, $a, $b, $cumulative)
	{
		if (is_array($value) || is_array($a) || is_array($b) || is_array($cumulative)) {
			return self::evaluateArrayArguments([self::class, __FUNCTION__], $value, $a, $b, $cumulative);
		}

		try {
			$value = DistributionValidations::validateFloat($value);
			$a = DistributionValidations::validateFloat($a);
			$b = DistributionValidations::validateFloat($b);
			$cumulative = DistributionValidations::validateBool($cumulative);
		} catch (Exception $e) {
			return $e->getMessage();
		}

		if (($value < 0) || ($a <= 0) || ($b <= 0)) {
			return ExcelError::NAN();
		}

		return self::calculateDistribution($value, $a, $b, $cumulative);
	}

	/**
	 * GAMMAINV.
	 *
	 * Returns the inverse of the Gamma distribution.
	 *
	 * For a probability so far into the upper tail that the forward-CDF series
	 * approximation plateaus below it, the root cannot be bracketed; the result
	 * is capped at the alpha*beta*5 search ceiling rather than diverging.
	 *
	 * @param mixed $probability Float probability at which you want to evaluate the distribution
	 *                      Or can be an array of values
	 * @param mixed $alpha Parameter to the distribution as a float
	 *                      Or can be an array of values
	 * @param mixed $beta Parameter to the distribution as a float
	 *                      Or can be an array of values
	 *
	 * @return array<mixed>|float|string If an array of numbers is passed as an argument, then the returned result will also be an array
	 *            with the same dimensions
	 */
	public static function inverse($probability, $alpha, $beta)
	{
		if (is_array($probability) || is_array($alpha) || is_array($beta)) {
			return self::evaluateArrayArguments([self::class, __FUNCTION__], $probability, $alpha, $beta);
		}

		try {
			$probability = DistributionValidations::validateProbability($probability);
			$alpha = DistributionValidations::validateFloat($alpha);
			$beta = DistributionValidations::validateFloat($beta);
		} catch (Exception $e) {
			return $e->getMessage();
		}

		if (($alpha <= 0.0) || ($beta <= 0.0)) {
			return ExcelError::NAN();
		}

		return self::calculateInverse($probability, $alpha, $beta);
	}

	/**
	 * GAMMALN.
	 *
	 * Returns the natural logarithm of the gamma function.
	 *
	 * @param mixed $value Float Value at which you want to evaluate the distribution
	 *                      Or can be an array of values
	 *
	 * @return array<mixed>|float|string If an array of numbers is passed as an argument, then the returned result will also be an array
	 *            with the same dimensions
	 */
	public static function ln($value)
	{
		if (is_array($value)) {
			return self::evaluateSingleArgumentArray([self::class, __FUNCTION__], $value);
		}

		try {
			$value = DistributionValidations::validateFloat($value);
		} catch (Exception $e) {
			return $e->getMessage();
		}

		if ($value <= 0) {
			return ExcelError::NAN();
		}

		$result = self::logGamma($value);

		// logGamma returns its MAX_VALUE sentinel when the result would overflow.
		return ($result >= self::MAX_VALUE) ? ExcelError::NAN() : $result;
	}
}

```