Use CSVs not ARFFs. Transpose the dataset upon loading.

src/mlpack/methods/naive_bayes/nbc_test.cc

@@ -15,8 +15,8 @@ BOOST_AUTO_TEST_CASE(SimpleNBCTest) {
   size_t number_of_classes_ = 2;
 
   arma::mat train_data, train_res, calc_mat;
-  train_data.load(filename_train_);
-  train_res.load(train_result_);
+  train_data.load(filename_train_, arma::auto_detect, true, true);
+  train_res.load(train_result_, arma::auto_detect, true, true);
 
   CLI::GetParam<int>("nbc/classes") = number_of_classes_;
   SimpleNaiveBayesClassifier nbc_test_(train_data);
@@ -41,8 +41,8 @@ BOOST_AUTO_TEST_CASE(SimpleNBCTest) {
 
   arma::mat test_data, test_res;
   arma::vec test_res_vec, calc_vec;
-  test_data.load(filename_test_);
-  test_res.load(test_result_);
+  test_data.load(filename_test_, arma::auto_detect, true, true);
+  test_res.load(test_result_, arma::auto_detect, true, true);
   nbc_test_.Classify(test_data, calc_vec);
 
   size_t number_of_datum = test_data.n_cols;

src/mlpack/methods/naive_bayes/trainSet.csv

@@ -1,13 +1,3 @@
-@relation test
-
-% These should get 100% classification with k < 30
-@attribute a real
-@attribute b real
-@attribute c real
-@attribute d real
-@attribute class {0,1}
-
-@data
 3,3,3,3,0
 3,4,4,3,0
 3,4,4,3,0