diff --git a/src/fsrs_optimizer/fsrs_optimizer.py b/src/fsrs_optimizer/fsrs_optimizer.py
index a4bc738..2aa03e2 100644
--- a/src/fsrs_optimizer/fsrs_optimizer.py
+++ b/src/fsrs_optimizer/fsrs_optimizer.py
@@ -1541,6 +1541,11 @@ def moving_average(data, window_size=365 // 20):
 
     def evaluate(self, save_to_file=True):
         my_collection = Collection(DEFAULT_PARAMETER, self.float_delta_t)
+        if "tensor" not in self.dataset.columns:
+            self.dataset["tensor"] = self.dataset.progress_apply(
+                lambda x: lineToTensor(list(zip([x["t_history"]], [x["r_history"]]))[0]),
+                axis=1,
+            )
         stabilities, difficulties = my_collection.batch_predict(self.dataset)
         self.dataset["stability"] = stabilities
         self.dataset["difficulty"] = difficulties