Generic function to find restricted mean survival of a distribution

Generic function to find the restricted mean of a distribution, given the equivalent probability distribution function using numeric intergration.

rmst_generic(pdist, t, start = 0, matargs = NULL, ...)

Arguments

pdist	Probability distribution function, for example, pnorm for the normal distribution, which must be defined in the current workspace. This should accept and return vectorised parameters and values. It should also return the correct values for the entire real line, for example a positive distribution should have pdist(x)==0 for \(x<0\).
t	Vector of times to which rmst is evaluated
start	Optional left-truncation time or times. The returned restricted mean survival will be conditioned on survival up to this time.
matargs	Character vector giving the elements of ... which represent vector parameters of the distribution. Empty by default. When vectorised, these will become matrices. This is used for the arguments gamma and knots in qsurvspline.
...	The remaining arguments define parameters of the distribution pdist. These MUST be named explicitly.

Value

Vector of restricted means survival times of the distribution at p.

Details

This function is used by default for custom distributions for which an rmst function is not provided.

This assumes a suitably smooth, continuous distribution.

Author

Christopher Jackson <chris.jackson@mrc-bsu.cam.ac.uk>

Examples

rmst_lnorm(500, start=250, meanlog=7.4225, sdlog = 1.1138)
#> [1] 237.8849
rmst_generic(plnorm, 500, start=250, c(0.025, 0.975), meanlog=7.4225, sdlog = 1.1138)
#> [1] 237.8849
# must name the arguments