Partial derivatives of pi (net survival at tau) by theta
#' @description Partial derivatives of cure fraction (or net survival at tau) by theta from non-mixture model with distribution "tneh".
dpidtheta_adtneh2(
z_tau = z_tau,
z_alpha = z_alpha,
x = x,
object,
cumLexctopred = NULL
)
Covariates matrix acting on time-to-null parameter.
Covariates matrix acting on parameter alpha of the density of time-to-null excess hazard model
time at which the estimates are predicted
ouput from model implemented in curesurv
pre prediction (obtained from cumLexc_ad2_topred), if NULL then it is calculated