Probabilities::InverseChiSquareCDFInv Function

double InverseChiSquareCDFInv(double p, int Nu);

Inverse Chi-Square percent point function (PPF, quantile / inverse CDF).

#NameTypeDescription
1pdoubleProbability, real value on the closed interval [0,1].
2NuintDefines distribution degrees of freedom, positive integer (Nu>0).

Returns: the value x such that InverseChiSquareCDF(x,Nu)=p. Computed by bisection of the CDF on [EPS, 1e6]. Returns NaN if Nu<=0 or p is outside [0,1].

Remarks:

The percent point function is the inverse of the cumulative distribution function:

CDFInv(p | nu) = F^(-1)(p | nu) where F(x | nu) = Q(nu/2,1/2x) = p .

No closed form exists; the result is obtained by numerically inverting the CDF with a bisection method (tolerance EPS). Returns NaN for p outside [0,1] or Nu<=0.

See Also: Probabilities::InverseChiSquareCDF, Probabilities::InverseChiSquarePDF
Declared in Dew::Math::Units::Probabilities · Dew.Math/Units.Probabilities.h · Cross-compiler