## ----include = FALSE----------------------------------------------------------
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  fig.width = 7,
  fig.height = 4.5
)
options(hcinfer.use_emoji = FALSE)

## -----------------------------------------------------------------------------
library(hcinfer)

schools <- PublicSchools2
schools$income_scaled <- schools$income / 10000

fit <- lm(expenditure ~ income_scaled + south, data = schools)
fit

## -----------------------------------------------------------------------------
boot <- boot_pairs(fit, B = 2000, seed = 123)
boot

## -----------------------------------------------------------------------------
coef(boot)
vcov(boot)
confint(boot)

## -----------------------------------------------------------------------------
confint(boot, level = 0.99, type = "basic")
confint(boot, parm = "south", level = 0.90)

## ----bootstrap-ci-plot, fig.alt = "Pairs bootstrap confidence intervals for the public-schools regression coefficients."----
plot(boot)

## -----------------------------------------------------------------------------
data.frame(
  term = boot$table$term,
  ols = sqrt(diag(vcov(fit))),
  bootstrap = boot$table$std_error,
  hcbeta = sqrt(diag(vcov(hcinfer(fit, type = "hcbeta")))),
  hc3 = sqrt(diag(vcov(hcinfer(fit, type = "hc3"))))
)

## -----------------------------------------------------------------------------
a <- boot_pairs(fit, B = 1000, seed = 7)
b <- boot_pairs(fit, B = 1000, seed = 7)
identical(a$replicates, b$replicates)

## ----eval = FALSE-------------------------------------------------------------
# boot_pairs(fit, B = 10000, cores = 4, seed = 1)