Phased Bi-Weibull Distribution

Parameters

The parameters are constrained by the following relation

When you manually specify the parameter values, EasyFit automatically computes the parameter based on this equation, so you don't need to calculate it by hand.

Domain

Probability Density Function

Cumulative Distribution Function

Worksheet and VBA Functions

The following worksheet and VBA functions are available for this distribution:

Description	VBA Functions	Worksheet Functions
Distribution Fitting	-	=DistFit("PhasedBiWeib";Data;[Options]1)
Probability Density Function	PhasedBiWeibPdf(x,alpha1,beta1,gamma1,alpha2,beta2,gamma2)	=PhasedBiWeibPdf(alpha1;beta1;gamma1;alpha2;beta2;gamma2) =DistPdf("PhasedBiWeib(alpha1;beta1;gamma1;alpha2;beta2;gamma2)";x)
Cumulative Distribution Function	PhasedBiWeibCdf(x,alpha1,beta1,gamma1,alpha2,beta2,gamma2)	=PhasedBiWeibCdf(alpha1;beta1;gamma1;alpha2;beta2;gamma2) =DistCdf("PhasedBiWeib(alpha1;beta1;gamma1;alpha2;beta2;gamma2)";x)
Survival Function	PhasedBiWeibSurv(x,alpha1,beta1,gamma1,alpha2,beta2,gamma2)	=DistSurv("PhasedBiWeib(alpha1;beta1;gamma1;alpha2;beta2;gamma2)";x)
Hazard Function	PhasedBiWeibHaz(x,alpha1,beta1,gamma1,alpha2,beta2,gamma2)	=PhasedBiWeibHaz(alpha1;beta1;gamma1;alpha2;beta2;gamma2) =DistHaz("PhasedBiWeib(alpha1;beta1;gamma1;alpha2;beta2;gamma2)";x)
Cumulative Hazard Function	PhasedBiWeibCumHaz(x,alpha1,beta1,gamma1,alpha2,beta2,gamma2)	=DistCumHaz("PhasedBiWeib(alpha1;beta1;gamma1;alpha2;beta2;gamma2)";x)
Inverse CDF (Quantile Function)	PhasedBiWeibInv(P,alpha1,beta1,gamma1,alpha2,beta2,gamma2)	=PhasedBiWeibInv(alpha1;beta1;gamma1;alpha2;beta2;gamma2) =DistInv("PhasedBiWeib(alpha1;beta1;gamma1;alpha2;beta2;gamma2)";P)
Random Numbers	PhasedBiWeibRand(alpha1,beta1,gamma1,alpha2,beta2,gamma2)	=PhasedBiWeibRand(alpha1;beta1;gamma1;alpha2;beta2;gamma2) =DistRand("PhasedBiWeib(alpha1;beta1;gamma1;alpha2;beta2;gamma2)")

1. The Options parameter is optional. Possible options: "gamma1=value"  (example: "gamma1=0")