OwlCyberSecurity - MANAGER
Edit File: ErfC.php
<?php namespace PhpOffice\PhpSpreadsheet\Calculation\Engineering; use PhpOffice\PhpSpreadsheet\Calculation\ArrayEnabled; use PhpOffice\PhpSpreadsheet\Calculation\Functions; use PhpOffice\PhpSpreadsheet\Calculation\Information\ExcelError; class ErfC { use ArrayEnabled; /** * ERFC. * * Returns the complementary ERF function integrated between x and infinity * * Note: In Excel 2007 or earlier, if you input a negative value for the lower bound argument, * the function would return a #NUM! error. However, in Excel 2010, the function algorithm was * improved, so that it can now calculate the function for both positive and negative x values. * PhpSpreadsheet follows Excel 2010 behaviour, and accepts nagative arguments. * * Excel Function: * ERFC(x) * * @param mixed $value The float lower bound for integrating ERFC * Or can be an array of values * * @return array|float|string * If an array of numbers is passed as an argument, then the returned result will also be an array * with the same dimensions */ public static function ERFC($value) { if (is_array($value)) { return self::evaluateSingleArgumentArray([self::class, __FUNCTION__], $value); } if (is_numeric($value)) { return self::erfcValue($value); } return ExcelError::VALUE(); } private const ONE_SQRT_PI = 0.564189583547756287; /** * Method to calculate the erfc value. * * @param float|int|string $value * * @return float */ private static function erfcValue($value) { $value = (float) $value; if (abs($value) < 2.2) { return 1 - Erf::erfValue($value); } if ($value < 0) { return 2 - self::erfcValue(-$value); } $a = $n = 1; $b = $c = $value; $d = ($value * $value) + 0.5; $q2 = $b / $d; do { $t = $a * $n + $b * $value; $a = $b; $b = $t; $t = $c * $n + $d * $value; $c = $d; $d = $t; $n += 0.5; $q1 = $q2; $q2 = $b / $d; } while ((abs($q1 - $q2) / $q2) > Functions::PRECISION); return self::ONE_SQRT_PI * exp(-$value * $value) * $q2; } }