a list of formulas that define age (time) - dependency. Default: list(at="a", f1t="f1", Qt="Q*exp(theta*t)", ft="f", bt="b", mu0t="mu0*exp(theta*t)")
step
An interval between two observations, a random uniformally-distributed value is then added to this step.
tstart
Starting time (age).
Can be a number (30 by default) or a vector of two numbers: c(a, b) - in this case, starting value of time
is simulated via uniform(a,b) distribution.
tend
A number, defines final time (105 by default).
ystart
A starting value of covariates.
sd0
A standard deviation for modelling the next covariate value, sd0 = 1 by default.
nobs
A number of observations (lines) for individual observations.
Value
A table with simulated data.
References
Yashin, A. et al (2007), Health decline, aging and mortality: how are they related?
Biogerontology, 8(3), 291-302.<DOI:10.1007/s10522-006-9073-3>.
Examples
library(stpm)
dat <- simdata_time_dep(N=100)
head(dat)