public function f($x)
    {
        if (!is_numeric($x)) {
            throw new \InvalidArgumentException('x variable must be numeric value.');
        }

        $float_fx = exp(-0.5 * pow(($x - $this->float_mu) / $this->float_sigma, 2)) / ($this->float_sigma * sqrt(2 * pi()));

        if ($this->int_precision) {
            return round($float_fx, $this->int_precision);
        }

        return $float_fx;
    }
public function f($x)
    {
        if (!is_numeric($x)) {
            throw new \InvalidArgumentException('x variable must be numeric value.');
        }

        $float_fx = exp(-0.5 * pow(($x - $this->float_mu) / $this->float_sigma, 2)) / ($this->float_sigma * sqrt(2 * pi()));

        if ($this->int_precision) {
            return round($float_fx, $this->int_precision);
        }

        return $float_fx;
    }
public function f ( $ x ) { if ( ! is_numeric ( $ x ) ) { throw new \ InvalidArgumentException ( 'x variable must be numeric value.' ) ; } $ float_fx = exp ( - 0.5 * pow ( ( $ x - $ this -> float_mu ) / $ this -> float_sigma , 2 ) ) / ( $ this -> float_sigma * sqrt ( 2 * pi ( ) ) ) ; if ( $ this -> int_precision ) { return round ( $ float_fx , $ this -> int_precision ) ; } return $ float_fx ; }
Function that returns normal distribution value for given x.

@see NormalDistribution::precision()
@throw \InvalidArgumentException If x is not numerical value.
@param  float $x
@access public
@return float
Function that returns normal distribution value for given x .