Hazard and cumulative hazard functions for distributions which are built into flexsurv, and whose distribution functions are in base R.

`hexp(x, rate = 1, log = FALSE)`Hexp(x, rate = 1, log = FALSE)

hgamma(x, shape, rate = 1, log = FALSE)

Hgamma(x, shape, rate = 1, log = FALSE)

hlnorm(x, meanlog = 0, sdlog = 1, log = FALSE)

Hlnorm(x, meanlog = 0, sdlog = 1, log = FALSE)

hweibull(x, shape, scale = 1, log = FALSE)

Hweibull(x, shape, scale = 1, log = FALSE)

x

Vector of quantiles

rate

Rate parameter (exponential and gamma)

log

Compute log hazard or log cumulative hazard

shape

Shape parameter (Weibull and gamma)

meanlog

Mean on the log scale (log normal)

sdlog

Standard deviation on the log scale (log normal)

scale

Scale parameter (Weibull)

Hazard (functions beginning 'h') or cumulative hazard (functions beginning 'H').

For the exponential and the Weibull these are available analytically, and so are programmed here in numerically stable and efficient forms.

For the gamma and log-normal, these are simply computed as minus the log of the survivor function (cumulative hazard) or the ratio of the density and survivor function (hazard), so are not expected to be robust to extreme values or quick to compute.