f4: Function Four
In NPHMC: Sample Size Calculation for the Proportional Hazards Mixture Cure Model

f4	R Documentation

Function Four

The fourth integrate function

f4(t, accrualtime, followuptime, accrualdist, beta0, gamma0, pi0, survdist,
 k, lambda0)

`t`	time variable
`accrualtime`	length of accrual period.
`followuptime`	length of follow-up time.
`accrualdist`	accrual pattern. It can be "`uniform`", "`increasing`" or "`decreasing`".
`beta0`	log hazard ratio of uncured patients
`gamma0`	log odds ratio of cure rates between the two arms
`pi0`	cure rate for the control arm, which is between 0 and 1.
`survdist`	survival distribution of uncured patients. It can be "`exp`" or "`weib`".
`k`	if `survdist` = "`weib`", the shape parameter `k` needs to be specified. By default `k` = 1, which refers to the exponential distribution.
`lambda0`	the scale parameter of exponential distribution or Weibull distribution for survival times of uncured patients in the control arm. The density function of Weibull distribution with shape parameter `k` and scale parameter λ_0 is given by f(t)=λ_{0}k(λ_{0}t)^{k-1}\exp(-(λ_{0}t)^k), for t > 0, and the corresponding survival distribution is S(t)=\exp(-(λ_0 t)^k).