public static function PHPExcel_Calculation_Engineering::BESSELK in Loft Data Grids 6.2
Same name and namespace in other branches
- 7.2 vendor/phpoffice/phpexcel/Classes/PHPExcel/Calculation/Engineering.php \PHPExcel_Calculation_Engineering::BESSELK()
* 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 Functions *
Parameters
float $x The value at which to evaluate the function.: * If x is nonnumeric, BESSELK returns the #VALUE! error value. * @param integer $ord The order of the Bessel function. If n is not an integer, it is truncated. * If $ord is nonnumeric, BESSELK returns the #VALUE! error value. * If $ord < 0, BESSELK returns the #NUM! error value. * @return float *
File
- vendor/
phpoffice/ phpexcel/ Classes/ PHPExcel/ Calculation/ Engineering.php, line 937
Class
- PHPExcel_Calculation_Engineering
- PHPExcel_Calculation_Engineering
Code
public static function BESSELK($x, $ord) {
$x = is_null($x) ? 0.0 : PHPExcel_Calculation_Functions::flattenSingleValue($x);
$ord = is_null($ord) ? 0.0 : PHPExcel_Calculation_Functions::flattenSingleValue($ord);
if (is_numeric($x) && is_numeric($ord)) {
if ($ord < 0 || $x == 0.0) {
return PHPExcel_Calculation_Functions::NaN();
}
switch (floor($ord)) {
case 0:
return self::_Besselk0($x);
break;
case 1:
return self::_Besselk1($x);
break;
default:
$fTox = 2 / $x;
$fBkm = self::_Besselk0($x);
$fBk = self::_Besselk1($x);
for ($n = 1; $n < $ord; ++$n) {
$fBkp = $fBkm + $n * $fTox * $fBk;
$fBkm = $fBk;
$fBk = $fBkp;
}
}
return is_nan($fBk) ? PHPExcel_Calculation_Functions::NaN() : $fBk;
}
return PHPExcel_Calculation_Functions::VALUE();
}