objfunction_betapw: Objective Function for The Finding of Censor Hazard Function...
In TwoArmSurvSim: Simulate Survival Data for Randomized Clinical Trials

objective function for the finding of censor hazard function parameter.

1	objfunction_betapw(x,lambda,gamma,gammac,theta,ebx,groupfreq,censordist,timeinterval)

`x`	Censor hazard function parameter. For exponential or weibull censor hazard, x is lambda, for uniform hazard, x is the maximum time of the censoring window.
`lambda`	lamda for event hazard function
`gamma`	gamma for event hazard function
`gammac`	gamma for censor hazard function. THis is required if the censoring hazard function is weibull
`theta`	Dropout rate
`ebx`	exp(beta*x), if there's no covariates, ebx=1.
`groupfreq`	frequence of each level of ebx value
`censordist`	censor hazard function distribution
`timeinterval`	time intervals for piecewise baseline hazard function