Minor bugfixes for LSTM example. (#246)

Author: rcurtin

cpp/lstm/dga_detection/lstm_dga_detection_predict.cpp

@@ -15,6 +15,10 @@
  * To keep the model small and the code fast, we use `float` as a datatype
  * instead of the default `double`.
  */
+
+// This must be defined to avoid RNN::serialize() throwing an error---we know
+// what we are doing and have manually registered the layer types we care about.
+#define MLPACK_ANN_IGNORE_SERIALIZATION_WARNING
 #include <mlpack.hpp>
 
 // To keep compilation time and program size down, we only register
@@ -142,10 +146,11 @@ int main(int argc, char** argv)
     const float benignLikelihood = ComputeLikelihood(benignOutput, response);
     const float maliciousLikelihood = ComputeLikelihood(maliciousOutput,
         response);
+    const float score = benignLikelihood - maliciousLikelihood;
 
     if (benignLikelihood > maliciousLikelihood)
-      cout << "benign" << endl;
+      cout << "benign (score " << score << ")" << std::endl;
     else
-      cout << "malicious" << endl;
+      cout << "malicious (score " << -score << ")" << std::endl;
   }
 }

cpp/lstm/dga_detection/lstm_dga_detection_train.cpp

@@ -26,6 +26,10 @@
  * Train the model on the `dga_domains.csv` file in the data/ directory in the
  * repository (once you have run `scripts/download_data_set.py`).
  */
+
+// This must be defined to avoid RNN::serialize() throwing an error---we know
+// what we are doing and have manually registered the layer types we care about.
+#define MLPACK_ANN_IGNORE_SERIALIZATION_WARNING
 #include <mlpack.hpp>
 
 // To keep compilation time and program size down, we only register
@@ -115,7 +119,7 @@ void PrepareData(const vector<string>& domains,
 size_t ComputeCorrect(const arma::fcube& benignPredictions,
                       const arma::fcube& maliciousPredictions,
                       const arma::fcube& labels,
-                      const arma::uvec& sequenceLengths,
+                      const arma::urowvec& sequenceLengths,
                       const bool malicious)
 {
   size_t correct = 0;