Gracefully handle the single-object case in svm

kiudee · Sep 25, 2020 · b34e3ef · b34e3ef
1 parent a0ed20b
commit b34e3ef
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/csrank/core/pairwise_svm.py b/csrank/core/pairwise_svm.py
@@ -75,7 +75,6 @@ def fit(self, X, Y, **kwargs):
         """
         self._pre_fit()
         _n_instances, self.n_objects_fit_, self.n_object_features_fit_ = X.shape
-        x_train, y_single = self._convert_instances_(X, Y)
         if self.use_logistic_regression:
             self.model_ = LogisticRegression(
                 C=self.C,
@@ -93,6 +92,10 @@ def fit(self, X, Y, **kwargs):
             )
             logger.info("Linear SVC model ")
 
+        if self.n_objects_fit_ < 2:
+            # Nothing to learn, cannot create pairwise instances.
+            return self
+        x_train, y_single = self._convert_instances_(X, Y)
         if self.normalize:
             std_scalar = StandardScaler()
             x_train = std_scalar.fit_transform(x_train)