simdata_gamma_frailty {stpm} | R Documentation |
This script simulates data using familial frailty model. We use the following variation: gamma(mu, ssq), where mu is the mean and ssq is sigma square. See: https://www.rocscience.com/help/swedge/webhelp/swedge/Gamma_Distribution.htm
Description
This script simulates data using familial frailty model. We use the following variation: gamma(mu, ssq), where mu is the mean and ssq is sigma square. See: https://www.rocscience.com/help/swedge/webhelp/swedge/Gamma_Distribution.htm
Usage
simdata_gamma_frailty(
N = 10,
f = list(at = "-0.05", f1t = "80", Qt = "2e-8", ft = "80", bt = "5", mu0t = "1e-3"),
step = 1,
tstart = 30,
tend = 105,
ystart = 80,
sd0 = 1,
nobs = NULL,
gamma_mu = 1,
gamma_ssq = 0.5
)
Arguments
N |
Number of individuals. |
f |
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. |
gamma_mu |
A parameter which is a mean value, default = 1 |
gamma_ssq |
A sigma squared, default = 0.5. |
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_gamma_frailty(N=10)
head(dat)