## ----include = FALSE----------------------------------------------------------
knitr::opts_chunk$set(collapse = TRUE, comment = "#>", eval = FALSE)

## -----------------------------------------------------------------------------
# library(bqmm)
# bqmm(y ~ x + (1 | group), data, tau = 0.5)

## -----------------------------------------------------------------------------
# bqmm(y ~ x + (1 + x | group), data, tau = 0.5)            # diagonal
# bqmm(y ~ x + (1 + x | group), data, tau = 0.5,
#      cov = "unstructured")                                # correlated

## -----------------------------------------------------------------------------
# fit <- bqmm(y ~ x + (1 + x | group), data, tau = 0.5, cov = "unstructured")
# VarCorr(fit)
# attr(VarCorr(fit), "correlation")

## -----------------------------------------------------------------------------
# bqmm(y ~ x + (1 | school/classroom), data, tau = 0.5)    # nested
# bqmm(y ~ x + (1 | school) + (1 | neighbourhood), data, tau = 0.5)  # crossed