In jeksterslabds/jeksterslabRlinreg: Jekster's Lab Linear Regression Utilities

knitr::opts_chunk$set(
  error = TRUE,
  collapse = TRUE,
  comment = "#>",
  out.width = "100%"
)

# The Linear Regression Model: Leverage {#linreg-estimation-leverage-example}

library(testthat)
library(jeksterslabRlinreg)

Data

See jeksterslabRdatarepo::wages.matrix() for the data set used in this example.

X <- jeksterslabRdatarepo::wages.matrix[["X"]]
# age is removed
X <- X[, -ncol(X)]
y <- jeksterslabRdatarepo::wages.matrix[["y"]]
head(X)
head(y)

Leverage

result_h <- as.vector(h(X))

`lm()` function

lmobj <- lm(
  wages ~ gender + race + union + education + experience,
  data = jeksterslabRdatarepo::wages
)
lm_h <- as.vector(hatvalues(lmobj))

context("Test linreg-estimation-leverage")
test_that("result_h.", {
  expect_equivalent(
    length(result_h),
    length(lm_h)
  )
  for (i in seq_along(result_h)) {
    expect_equivalent(
      round(result_h[i], digits = 0),
      round(lm_h[i], digits = 0)
    )
  }
})