Probabilities.FatigueLifeCDFInv Method

Overload List

#SignatureDescription
1procedure FatigueLifeCDFInv(const P: TDenseMtxVec; Mu: Double; gamma: Double; beta: Double; const Res: TDenseMtxVec);Fatigue Life PPF (vectorized).
2function FatigueLifeCDFInv(p: Double; Mu: Double; gamma: Double; beta: Double): Double;Fatigue life (Birnbaum-Saunders) percent point function (PPF, quantile / inverse CDF).

Overload 1: procedure FatigueLifeCDFInv(const P: TDenseMtxVec; Mu: Double; gamma: Double; beta: Double; const Res: TDenseMtxVec);

Fatigue Life PPF (vectorized).

#NameDescription
1PDefines distribution probabilities, real vector or matrix with values within closed interval [0,1].
2MuDefines distribution location parameter.
3gammaDefines distribution shape parameter. gamma must be a positive scalar.
4betaDefines distribution scale parameter. beta must be a positive scalar.
5ResAfter calculation stores the PPF calculated from P, m, gamma and beta. Length and Complex properties of Res are adjusted automatically to match Length and Complex properties of P.

Result: stored in self (calling object)

Overload 2: function FatigueLifeCDFInv(p: Double; Mu: Double; gamma: Double; beta: Double): Double;

Fatigue life (Birnbaum-Saunders) percent point function (PPF, quantile / inverse CDF).

#NameDescription
1pProbability, real value on the closed interval [0,1].
2MuDistribution location parameter, real value.
3gammaDistribution shape parameter. gamma must be a positive scalar (gamma>0).
4betaDistribution scale parameter. beta must be a positive scalar (beta>0).

Returns: Double - the value x such that FatigueLifeCDF(x,Mu,gamma,beta)=p. Parameters gamma and beta must be positive and the probability p must lie on [0,1], otherwise the result is NaN.

Remarks:

The inverse CDF has a closed form. Let w=gamma Phi^(-1)(p) where Phi^(-1) is the standard normal quantile; then with z=(x-mu)/beta the relation w=sqrt(z)-sqrt(1/z) inverts to a quadratic in z:

CDFInv(p | mu,gamma,beta) = mu + beta z , z = 1/2( w^2+2 +/- sqrt((w^2+2)^2-4) ) , w=gamma Phi^(-1)(p) .

The "+" root is taken for p>1/2p>1/2 and the "-" root for p<1/2p<1/2. Returns NaN for p outside [0,1], gamma<=0 or beta<=0.

See Also: Probabilities.FatigueLifePDF, Probabilities.FatigueLifeCDF