Made the loss value management a little more conservative.

dlib/dnn/trainer.h

@@ -701,7 +701,7 @@ namespace dlib
                                 test_steps_without_progress = 0;
                                 // Empty out some of the previous loss values so that test_steps_without_progress 
                                 // will decrease below test_iter_without_progress_thresh.  
-                                for (int cnt = 0; cnt < previous_loss_values_dump_amount && test_previous_loss_values.size() > 0; ++cnt)
+                                for (int cnt = 0; cnt < test_previous_loss_values_dump_amount && test_previous_loss_values.size() > 0; ++cnt)
                                     test_previous_loss_values.pop_front();
                             }
                         }
@@ -879,7 +879,8 @@ namespace dlib
             prob_loss_increasing_thresh = prob_loss_increasing_thresh_default_value;
             updated_net_since_last_sync = false;
             sync_file_reloaded = false;
-            previous_loss_values_dump_amount = 100;
+            previous_loss_values_dump_amount = 400;
+            test_previous_loss_values_dump_amount = 100;
             start();
         }
 
@@ -890,7 +891,7 @@ namespace dlib
         friend void serialize(const dnn_trainer& item, std::ostream& out)
         {
             item.wait_for_thread_to_pause();
-            int version = 10;
+            int version = 11;
             serialize(version, out);
 
             size_t nl = dnn_trainer::num_layers;
@@ -917,6 +918,7 @@ namespace dlib
             serialize(item.test_steps_without_progress.load(), out);
             serialize(item.test_previous_loss_values, out);
             serialize(item.previous_loss_values_dump_amount, out);
+            serialize(item.test_previous_loss_values_dump_amount, out);
 
         }
         friend void deserialize(dnn_trainer& item, std::istream& in)
@@ -924,7 +926,7 @@ namespace dlib
             item.wait_for_thread_to_pause();
             int version = 0;
             deserialize(version, in);
-            if (version != 10)
+            if (version != 11)
                 throw serialization_error("Unexpected version found while deserializing dlib::dnn_trainer.");
 
             size_t num_layers = 0;
@@ -961,6 +963,7 @@ namespace dlib
             deserialize(ltemp, in); item.test_steps_without_progress = ltemp;
             deserialize(item.test_previous_loss_values, in);
             deserialize(item.previous_loss_values_dump_amount, in);
+            deserialize(item.test_previous_loss_values_dump_amount, in);
 
             if (item.devices.size() > 1)
             {
@@ -1269,6 +1272,7 @@ namespace dlib
 
         bool sync_file_reloaded;
         int previous_loss_values_dump_amount;
+        int test_previous_loss_values_dump_amount;
     };
 
 // ----------------------------------------------------------------------------------------