frailty_sd {TimeDepFrail}R Documentation

Frailty standard deviation and Variance for the 'Adapted Paik et al.'s Model'

Description

The function computes both the standard deviation and the variance of the time-dependent frailty of the 'Adapted Paik et al.'s Model'.

Recalling the frailty structure Z_{jk} = \alpha_j + \epsilon_{jk} as being composed by a constant group-dependent term (\alpha_j) and a time and group dependent term (\epsilon_{jk}), the frailty standard deviation (and variance) can be computed in two different way:

The final case only depends on what we want to observe.

Usage

frailty_sd(result, flag_fullsd = TRUE)

Arguments

result

S3 object of class 'AdPaik' returned by the main model output, that contains all the information for the computation of the frailty standard deviation.

flag_fullsd

Logical value. Do we want to compute the full frailty standard deviation? If so, the flag must be TRUE, otherwise, FALSE.

Value

S3 class object 'FrailtyDispersion' containing both two numerical vectors of length equal to the numbero of intervals of the time-domain:

Examples

# Consider the 'Academic Dropout dataset'
data(data_dropout)

# Define the variables needed for the model execution
formula <- time_to_event ~ Gender + CFUP + cluster(group)
time_axis <- c(1.0, 1.4, 1.8, 2.3, 3.1, 3.8, 4.3, 5.0, 5.5, 5.8, 6.0)
eps <- 1e-10
categories_range_min <- c(-8, -2, eps, eps, eps)
categories_range_max <- c(-eps, 0, 1 - eps, 1, 10)

# Call the main model

result <- AdPaikModel(formula, data_dropout, time_axis,
                      categories_range_min, categories_range_max, TRUE)

frailty_sd(result, TRUE)
frailty_sd(result, FALSE)


[Package TimeDepFrail version 0.0.0.9 Index]