tests/testthat/test-mean_update.R

In brieuclehmann/multibergm: Bayesian Exponential Random Graph Models for Multiple Networks

### mean_update tests

test_that("Zero prior covariance returns prior mean", {
  prior_cov <- diag(0, 2)
  prior_mean <- c(1, 1)
  obs_cov <- matrix(c(1, 0.1, 0.1, 2), nrow = 2)
  obs_data <- mvtnorm::rmvnorm(4, c(1, 1), obs_cov)

  expect_equal(mean_update(obs_data, obs_cov, prior_mean, prior_cov),
               prior_mean)
})


test_that("Identity covariance returns expected solution", {
  n <- 10

  prior_cov <- diag(1, 2)
  prior_mean <- c(1, 1)
  obs_cov <- diag(1, 2)
  obs_data <- mvtnorm::rmvnorm(n, prior_mean, obs_cov)

  post_mean <- (1 / (n + 1)) * (prior_mean + colSums(obs_data))

  set.seed(1)
  out <- mvtnorm::rmvnorm(1, post_mean, diag(1 / (n + 1), 2))[1, ]

  set.seed(1)
  expect_equal(mean_update(obs_data, obs_cov, prior_mean, prior_cov),
               out)
})