Extract variance estimates in the vcov form. — vcov.regmedint • regmedint

Extract variance estimates evaluated at a0, a1, m_cde, and c_cond.

# S3 method for regmedint
vcov(object, a0 = NULL, a1 = NULL, m_cde = NULL, c_cond = NULL, ...)

Arguments

object: An object of the regmedint class.
a0: A numeric vector of length 1
a1: A numeric vector of length 1
m_cde: A numeric vector of length 1 The mediator value at which the controlled direct effect (CDE) conditional on the adjustment covariates is evaluated. If not provided, the default value supplied to the call to regmedint will be used. Only the CDE is affected.
c_cond: A numeric vector of the same length as cvar. A set of covariate values at which the conditional natural effects are evaluated.
...: For compatibility with the generic. Ignored.

Value

A numeric matrix with the diagonals populated with variance estimates. Off-diagnonals are NA since these are not estimated.

Examples

library(regmedint)
data(vv2015)
regmedint_obj <- regmedint(data = vv2015,
                           ## Variables
                           yvar = "y",
                           avar = "x",
                           mvar = "m",
                           cvar = c("c"),
                           eventvar = "event",
                           ## Values at which effects are evaluated
                           a0 = 0,
                           a1 = 1,
                           m_cde = 1,
                           c_cond = 0.5,
                           ## Model types
                           mreg = "logistic",
                           yreg = "survAFT_weibull",
                           ## Additional specification
                           interaction = TRUE,
                           casecontrol = FALSE)
vcov(regmedint_obj)
#>             cde       pnde        tnie       tnde         pnie         te
#> cde  0.08657105         NA          NA         NA           NA         NA
#> pnde         NA 0.04430708          NA         NA           NA         NA
#> tnie         NA         NA 0.001373526         NA           NA         NA
#> tnde         NA         NA          NA 0.04498446           NA         NA
#> pnie         NA         NA          NA         NA 0.0007458327         NA
#> te           NA         NA          NA         NA           NA 0.04447903
#> pm           NA         NA          NA         NA           NA         NA
#>               pm
#> cde           NA
#> pnde          NA
#> tnie          NA
#> tnde          NA
#> pnie          NA
#> te            NA
#> pm   0.008316736
#> attr(,"args")
#> attr(,"args")$a0
#> [1] 0
#> 
#> attr(,"args")$a1
#> [1] 1
#> 
#> attr(,"args")$m_cde
#> [1] 1
#> 
#> attr(,"args")$c_cond
#> [1] 0.5
#> 
## Evaluate at different values
vcov(regmedint_obj, m_cde = 0, c_cond = 1)
#>             cde       pnde        tnie       tnde         pnie         te
#> cde  0.09049915         NA          NA         NA           NA         NA
#> pnde         NA 0.04416578          NA         NA           NA         NA
#> tnie         NA         NA 0.001334745         NA           NA         NA
#> tnde         NA         NA          NA 0.04593907           NA         NA
#> pnie         NA         NA          NA         NA 0.0007330485         NA
#> te           NA         NA          NA         NA           NA 0.04499562
#> pm           NA         NA          NA         NA           NA         NA
#>               pm
#> cde           NA
#> pnde          NA
#> tnie          NA
#> tnde          NA
#> pnie          NA
#> te            NA
#> pm   0.007902522
#> attr(,"args")
#> attr(,"args")$a0
#> [1] 0
#> 
#> attr(,"args")$a1
#> [1] 1
#> 
#> attr(,"args")$m_cde
#> [1] 0
#> 
#> attr(,"args")$c_cond
#> [1] 1
#>