TST: Added test for poisson regression

R-package/tests/testthat/test_poisson_regression.R

@@ -0,0 +1,13 @@
+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))
+})