private static function PHPExcel_Calculation_Engineering::_Besselk0 in Loft Data Grids 7.2

Same name and namespace in other branches

1. 6.2 vendor/phpoffice/phpexcel/Classes/PHPExcel/Calculation/Engineering.php \PHPExcel_Calculation_Engineering::_Besselk0()

1 call to PHPExcel_Calculation_Engineering::_Besselk0()

PHPExcel_Calculation_Engineering::BESSELK in vendor/phpoffice/phpexcel/Classes/PHPExcel/Calculation/Engineering.php

* BESSELK * * Returns the modified Bessel function Kn(x), which is equivalent to the Bessel functions evaluated * for purely imaginary arguments. * * Excel Function: * BESSELK(x,ord) * * @access public * @category Engineering…

File

vendor/phpoffice/phpexcel/Classes/PHPExcel/Calculation/Engineering.php, line 884

Class

PHPExcel_Calculation_Engineering

PHPExcel_Calculation_Engineering

Code

private static function _Besselk0($fNum) {
  if ($fNum <= 2) {
    $fNum2 = $fNum * 0.5;
    $y = $fNum2 * $fNum2;
    $fRet = -log($fNum2) * self::BESSELI($fNum, 0) + (-0.57721566 + $y * (0.4227842 + $y * (0.23069756 + $y * (0.0348859 + $y * (0.00262698 + $y * (0.0001075 + $y * 7.4E-6))))));
  }
  else {
    $y = 2 / $fNum;
    $fRet = exp(-$fNum) / sqrt($fNum) * (1.25331414 + $y * (-0.07832358 + $y * (0.02189568 + $y * (-0.01062446 + $y * (0.00587872 + $y * (-0.0025154 + $y * 0.00053208))))));
  }
  return $fRet;
}