udderquarterinfection: Udder Quarter Infection Data
In UdderQuarterInfectionData: Udder Quarter Infection Data

The udder quarter infection data contains the times to infection of the individual udder quarters of 100 cows during one lactation period. The 'cowid' variable contains the cow number. Each cow has 4 different quarters, with the variable 'quarter' referring to the specific quarter, i.e., RF: right front, RR: right rear, LF: left front, LR: left rear. The lactation number, i.e., the number of calvings that the cow has experienced, is given by the variable 'lactation'. If at least one infection occurs in a quarter during the lactation period, the 'status' variable is set to 1, and the interval [t1,t2] in which an infection takes place is given by the variables 'left' and 'right', where 'right' denotes the time with the first positive result, and 'left' the last time (with a negative result) before the first positive result. Only the first infection is contained in the data set. If no infection occurs, the 'status' variable is set to 1, and the last interval [t1,t2] in which the quarter was observed is put in the variables 'left' and 'right'.,

The following example analyses of this data set are currently available in the package:

Gamma_Frailty_Interval_Censoring

A dataframe with 4784 rows and 6 variables.

## Not run: 
## SHORT DATASET ANALYSIS ##

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)