update.brmcoda function

Update brmcoda models

This method allows for updating an existing brmcoda object.

## S3 method for class 'brmcoda'
update(object, formula. = NULL, newdata = NULL, newcomplr = NULL, ...)

Arguments

• object: A fitted brmcoda object to be updated.

• formula.: Changes to the formula; for details see update.formula and brmsformula.

• newdata: A data.frame or data.table

  containing data of all variables used in the analysis. It must include a composition and the same ID variable as the existing complr object.

• newcomplr: A complr object containing data of composition, ILR coordinates, and other variables used in the updated model.

• ...: Further arguments passed to brm.

Returns

A brmcoda with two elements - complr: An object of class complr used in the brm model.

• model: An object of class brmsfit, which contains the posterior draws along with many other useful information about the model.

Examples

if(requireNamespace("cmdstanr")){

# model with compositional predictor at between and within-person levels
fit <- brmcoda(complr = complr(data = mcompd, sbp = sbp, 
                               parts = c("TST", "WAKE", "MVPA", "LPA", "SB"), 
                               idvar = "ID"), 
              formula = Stress ~ bilr1 + bilr2 + bilr3 + bilr4 +
                                 wilr1 + wilr2 + wilr3 + wilr4 + (1 | ID), 
              chain = 1, iter = 500,
              backend = "cmdstanr")

# removing the effect of wilr1
fit1 <- update(fit, formula. = ~ . - wilr1)

# using only a subset
fit2 <- update(fit, newdata = mcompd[ID != 1])
}

See Also

brmcoda