/**
* Returns the moments of the distribution
*
* @param string $moments Which moments to compute. m for mean, v for variance, s for skew, k for kurtosis. Default 'mv'
* @return type array A dictionary containing the first four moments of the distribution
*/
public function stats($moments = 'mv')
{
return $this->calculator->getStats($moments, $this->mu, $this->variance);
}
/**
* Returns a random float between $minimum and $minimum plus $maximum
*
* @param float $df The degrees of freedeom. Default 1
* @return float The random variate.
*/
public function getRvs($df = 1)
{
$Z = parent::getRvs(0, 1);
$V = $this->chi->getRvs($df);
return $Z / sqrt($V / $df);
}
/**
* Returns a Cauchy-distributed random float
*
* @param float $mu The location parameter
* @param float $gamma The scale parameter
* @return float The random variate.
*/
public function getRvs($mu = 0.0, $gamma = 1.0)
{
$u = $this->normal->getRvs(0, 1);
$v = $this->normal->getRvs(0, 1);
return $gamma * ($u / $v) + $mu;
}
