Probabilities::GammaCDFInv Function

Overload List

#SignatureDescription
1double GammaCDFInv(double p, double a, double b);Gamma distribution inverse CDF (quantile / point percent function, PPF).
2void GammaCDFInv(TDenseMtxVec *P, double A, double B, TDenseMtxVec *Res);Gamma distribution PPF (vectorized).

Overload 1: double GammaCDFInv(double p, double a, double b);

Gamma distribution inverse CDF (quantile / point percent function, PPF).

#NameTypeDescription
1pdoubleProbability, real value on the closed interval [0,1].
2adoubleShape parameter, real value > 0.
3bdoubleScale parameter, real value > 0.

Returns: the value x with GammaCDF(x,a,b)=p for SHAPE parameter a and SCALE parameter b. Returns NAN when p < 0, p > 1, a <= 0 or b <= 0; returns 0 at p=0 and 1 at p=1.

Remarks:

Computes the inverse of the Gamma CDF (the quantile function)

inverse CDF(p| a,b ) = F^(-1)(p| a,b) , p(x)=CDF(x|a,b)

evaluated by a Newton-Raphson iteration on P(a,x/b)pP(a,x/b)-p, where Gamma is the Math387::Gamma function. Domain: p in [0,1], a > 0, b > 0. Behaviour: returns 0 at p=0 and 1 at p=1; for invalid parameters or p not in [0,1] returns NAN.

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

Overload 2: void GammaCDFInv(TDenseMtxVec *P, double A, double B, TDenseMtxVec *Res);

Gamma distribution PPF (vectorized).

#NameTypeDescription
1PTDenseMtxVec *Defines distribution probabilities, real vector or matrix with values within closed interval [0,1].
2AdoubleDefines distribution scale parameter. A must be a positive scalar.
3BdoubleDefines distribution shape parameter. B must be a positive scalar.
4ResTDenseMtxVec *After calculation stores the PPF calculated from P, A and B. Length and Complex properties of Res are adjusted automatically to match Length and Complex properties of P.
Declared in Dew::Math::Units::Probabilities · Dew.Math/Units.Probabilities.h · Cross-compiler