private static function PHPExcel_Calculation_Engineering::_Besselk1 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::_Besselk1()

1 call to PHPExcel_Calculation_Engineering::_Besselk1()

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 901

Class

PHPExcel_Calculation_Engineering

PHPExcel_Calculation_Engineering

Code

private static function _Besselk1($fNum) {
  if ($fNum <= 2) {
    $fNum2 = $fNum * 0.5;
    $y = $fNum2 * $fNum2;
    $fRet = log($fNum2) * self::BESSELI($fNum, 1) + (1 + $y * (0.15443144 + $y * (-0.6727857900000001 + $y * (-0.18156897 + $y * (-0.01919402 + $y * (-0.00110404 + $y * -4.686E-5)))))) / $fNum;
  }
  else {
    $y = 2 / $fNum;
    $fRet = exp(-$fNum) / sqrt($fNum) * (1.25331414 + $y * (0.23498619 + $y * (-0.0365562 + $y * (0.01504268 + $y * (-0.00780353 + $y * (0.00325614 + $y * -0.00068245))))));
  }
  return $fRet;
}