Extends the pwe function to allow for
vectorization over the hazard rates.
ppwe(hazard, end_of_study, cutpoints)matrix. A matrix of hazard rate parameters with number of
columns equal to the length of the cutpoints vector. The number of
rows can be anything, and is typically dictated by the number of MCMC
draws.
scalar. Length of the study; i.e. time at which endpoint will be evaluated.
vector. The change-point vector indicating time when the
hazard rates change. Note the first element of cutpoints should
always be 0.
A vector of (0, 1) probabilities from evaluation of the PWE
cumulative distribution function. Length of the vector matches the number
of rows of the hazard matrix parameter.