public static function CDF($x, int $d₁, int $d₂)
{
Support::checkLimits(self::LIMITS, ['x' => $x, 'd₁' => $d₁, 'd₂' => $d₂]);
$ᵈ¹ˣ／d₁x＋d₂ = $d₁ * $x / ($d₁ * $x + $d₂);
return Special::regularizedIncompleteBeta($ᵈ¹ˣ／d₁x＋d₂, $d₁ / 2, $d₂ / 2);
} /**
* The probabilty associated with the regression F Statistic
*
* F probability = F distribution CDF(F,d₁,d₂)
*
* where:
* F = F statistic
* d₁ = degrees of freedom 1
* d₂ = degrees of freedom 2
*
* ν = degrees of freedom
*
* @return number
*/
public function FProbability()
{
$F = $this->FStatistic();
$n = $this->n;
// Degrees of freedom
// Need to make sure the 1 in $d₁ should not be $this->fit_parameters;
$ν = $this->ν;
$d₁ = $n - $ν - 1;
$d₂ = $ν;
return F::CDF($F, $d₁, $d₂);
}
