Gamma_Frailty_Interval_Censoring {UdderQuarterInfectionData} | R Documentation |
Gamma Frailty Interval Censoring
Description
Application of the Gamma Frailty Interval Censoring Model on the Udder Quarter Infection Data Set. For more information see Details.
Usage
Gamma_Frailty_Interval_Censoring(print.level = 2)
Arguments
print.level |
Parameter of |
Details
This function fits a parametric Weibull baseline hazard frailty model with gamma distributed frailties for the udder quarter infection data taking into consideration the interval censored nature of the data. Further theoretical details can be found in the paper in the reference
Value
Returns a list with the NLM result in nlm
and the covariance matrix in covmat
.
R Code for Model
The source R code for this model can found:
in the
doc/Models_R_Code.R
file in the package installation folder.by accessing the function by calling
Gamma_Frailty_Interval_Censoring
(without brackets) orgetAnywhere("Gamma_Frailty_Interval_Censoring")
.
Author(s)
Klara Goethals
Luc Duchateau
References
Goethals, K., Ampe, B., Berkvens, D., Laevens, H., Janssen, P. and Duchateau, L. (2009). Modeling interval-censored, clustered cow udder quarter infection times through the shared gamma frailty model. Journal of Agricultural Biological and Environmental Statistics 14, 1-14.
Examples
## Not run:
library(UdderQuarterInfectionData)
data("udderquarterinfection")
Gamma_Frailty_Interval_Censoring()
# $nlm
# $nlm$minimum
# [1] 5670.491
#
# $nlm$estimate
# [1] 3.7967246 0.1201593 1.9672298 0.8590531
#
# $nlm$gradient
# [1] 0.0002924871 0.0017653292 -0.0005460029 0.0003265086
#
# $nlm$hessian
# [,1] [,2] [,3] [,4]
# [1,] 23.22965 -117.7682 -39.93813 -10.10561
# [2,] -117.76825 15471.4753 567.24283 1228.87332
# [3,] -39.93813 567.2428 664.76359 24.63047
# [4,] -10.10561 1228.8733 24.63047 147.76479
#
# $nlm$code
# [1] 1
#
# $nlm$iterations
# [1] 22
#
#
# $covmat
# [,1] [,2] [,3] [,4]
# [1,] 0.049281911 0.0001242730 0.0027853686 0.001872592
# [2,] 0.000124273 0.0001982213 -0.0001015391 -0.001623066
# [3,] 0.002785369 -0.0001015391 0.0017306214 0.000746460
# [4,] 0.001872592 -0.0016230660 0.0007464600 0.020269244
## End(Not run)