tests/testthat/test-model-variables.R

In stan-dev/cmdstanr: R Interface to 'CmdStan'

context("model-variables")

set_cmdstan_path()

test_that("$variables() errors if version less than 2.27", {
  mod <- testing_model("bernoulli")
  ver <- cmdstan_version()
  .cmdstanr$VERSION <- "2.26.0"
  expect_error(
    mod$variables(),
    "$variables() is only supported for CmdStan 2.27 or newer",
    fixed = TRUE
  )
  .cmdstanr$VERSION <- ver
})

test_that("$variables() work correctly with example models", {
  mod <- testing_model("bernoulli")
  expect_equal(names(mod$variables()$data), c("N", "y"))
  expect_equal(names(mod$variables()$parameters), c("theta"))
  expect_equal(mod$variables()$data$N$type, "int")
  expect_equal(mod$variables()$data$N$dimensions, 0)
  expect_equal(mod$variables()$data$y$type, "int")
  expect_equal(mod$variables()$data$y$dimensions, 1)
  expect_equal(mod$variables()$parameters$theta$type, "real")
  expect_equal(mod$variables()$parameters$theta$dimensions, 0)
  expect_equal(length(mod$variables()$transformed_parameters), 0)
  expect_equal(length(mod$variables()$generated_quantities), 0)
  expect_true(is.list(mod$variables()$transformed_parameters))
  expect_true(is.list(mod$variables()$generated_quantities))

  mod <- testing_model("bernoulli_log_lik")
  expect_equal(names(mod$variables()$data), c("N", "y"))
  expect_equal(names(mod$variables()$parameters), c("theta"))
  expect_equal(names(mod$variables()$generated_quantities), c("log_lik"))
  expect_equal(mod$variables()$generated_quantities$log_lik$type, "real")
  expect_equal(mod$variables()$generated_quantities$log_lik$dimensions, 1)

  mod <- testing_model("logistic")
  expect_equal(names(mod$variables()$data), c("N", "K", "y", "X"))
  expect_equal(names(mod$variables()$parameters), c("alpha", "beta"))
  expect_equal(mod$variables()$data$N$type, "int")
  expect_equal(mod$variables()$data$N$dimensions, 0)
  expect_equal(mod$variables()$data$K$type, "int")
  expect_equal(mod$variables()$data$K$dimensions, 0)
  expect_equal(mod$variables()$data$y$type, "int")
  expect_equal(mod$variables()$data$y$dimensions, 1)
  expect_equal(mod$variables()$data$X$type, "real")
  expect_equal(mod$variables()$data$X$dimensions, 2)
  expect_equal(mod$variables()$parameters$alpha$type, "real")
  expect_equal(mod$variables()$parameters$alpha$dimensions, 0)
  expect_equal(mod$variables()$parameters$beta$type, "real")
  expect_equal(mod$variables()$parameters$beta$dimensions, 1)
})

test_that("$variables() work correctly with example models", {
  code <- "
  data {
    array[1,2,3,4,5,6,7,8] int y;
    array[1,2,3,4] vector[4] x;
  }
  parameters {
    real z;
  }
  transformed parameters {
    array[1,2,3] real p;
    array[2] matrix[2,3] pp;
  }
  "
  stan_file <- write_stan_file(code)
  mod <- cmdstan_model(stan_file)
  expect_equal(names(mod$variables()$data), c("y", "x"))
  expect_equal(names(mod$variables()$parameters), c("z"))
  expect_equal(names(mod$variables()$transformed_parameters), c("p", "pp"))
  expect_equal(mod$variables()$data$y$type, "int")
  expect_equal(mod$variables()$data$y$dimensions, 8)
  expect_equal(mod$variables()$data$x$type, "real")
  expect_equal(mod$variables()$data$x$dimensions, 5)
  expect_equal(mod$variables()$parameters$z$type, "real")
  expect_equal(mod$variables()$parameters$z$dimensions, 0)
  expect_equal(mod$variables()$transformed_parameters$p$type, "real")
  expect_equal(mod$variables()$transformed_parameters$p$dimensions, 3)
  expect_equal(mod$variables()$transformed_parameters$pp$type, "real")
  expect_equal(mod$variables()$transformed_parameters$pp$dimensions, 3)
})

test_that("$variables() errors on no stan_file", {
  code <- "
  parameters {
    real y;
  }
  model {
    y ~ std_normal();
  }
  "
  stan_file <- write_stan_file(code)
  mod <- cmdstan_model(stan_file)
  file.remove(stan_file)
  expect_error(
    mod$variables(),
    "The Stan file used to create the `CmdStanModel` object does not exist.",
    fixed = TRUE
  )
  mod_exe <- cmdstan_model(exe_file = mod$exe_file())
  expect_error(
    mod_exe$variables(),
    "'$variables()' cannot be used because the 'CmdStanModel' was not created with a Stan file.",
    fixed = TRUE
  )
})

test_that("$variables() works with #includes, both pre and post compilation.", {
  
  data_code <- "
    data {
      int N;
    }
  "
  model_code <- "
    #include data.stan
    parameters {
      vector[N] y;
    }
    model {
      y ~ std_normal();
    }
  "

  model_file <- write_stan_file(code = model_code)
  data_file <- write_stan_file(code = data_code, basename = "data.stan")

  mod <- cmdstan_model(
    stan_file = model_file,
    include_paths = dirname(data_file),
    compile = FALSE
  )

  vars_pre <- mod$variables()
  mod$compile()
  vars_post <- mod$variables()

  expect_equal(vars_pre, vars_post)
})