context('Test poisson regression model')

require(xgboost)

test_that("poisson regression works", {
  data(mtcars)
  bst <- xgboost(data = as.matrix(mtcars[,-11]),label = mtcars[,11],
                objective = 'count:poisson', nrounds=5)
  expect_equal(class(bst), "xgb.Booster")
  pred <- predict(bst,as.matrix(mtcars[, -11]))
  expect_equal(length(pred), 32)
  sqrt(mean( (pred - mtcars[,11]) ^ 2))
})