donaldmusgrove/bayesDP

% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/ppexp.R
\name{ppexp}
\alias{ppexp}
\title{Compute cdf of the piecewise exponential distribution}
\usage{
ppexp(q, x, cuts)
}
\arguments{
\item{q}{scalar. The time point at which the cdf is to be computed.}

\item{x}{vector or matrix. The hazard rate(s).}

\item{cuts}{vector. Times at which the rate changes, i.e., the interval cut
points. The first element of cuts should be 0, and cuts should be in
increasing order. Must be the same length as \code{x} (vector) or have the
same number of columns as \code{x} (matrix)}
}
\value{
The cumulative distribution function computed at time \code{q},
  hazard(s) \code{x}, and cut points \code{cuts}.
}
\description{
\code{ppexp} is used to compute the cumulative distribution
  function of the piecewise exponential distribution. The function is ported
  from R to C++ via code adapted from the \code{msm} package.
}
\details{
The code underlying \code{ppexp} is written in C++ and adapted from
  R code used in the \code{msm} package.
}
\examples{
# Single vector of hazard rates. Returns a single cdf value.
q    <- 12
x    <- c(0.25,0.3,0.35,0.4)
cuts <- c(0,6,12,18)
pp   <- ppexp(q,x,cuts)

# Matrix of multiple vectors of hazard rates. Returns 10 cdf values.
x  <- matrix(rgamma(4*10, 0.1, 0.1), nrow=10)
pp <- ppexp(q,x,cuts)
}