private function setShadowBlur($blur)
    {
        if ($blur !== null) {
            $this->shadowProperties['blur'] = (string) $this->getExcelPointsWidth($blur);
        }

        return $this;
    }
private function setShadowBlur($blur)
    {
        if ($blur !== null) {
            $this->shadowProperties['blur'] = (string) $this->getExcelPointsWidth($blur);
        }

        return $this;
    }
private function setShadowBlur ( $ blur ) { if ( $ blur !== null ) { $ this -> shadowProperties [ 'blur' ] = ( string ) $ this -> getExcelPointsWidth ( $ blur ) ; } return $ this ; }
Set Shadow Blur

@param float $blur

@return PHPExcel_Chart_Axis
Set Shadow Blur