use most recent trial if no SQ data for target trial in TransformToNewSQ (facebook#3225)

Summary:

see title. This ensures that status_quo_data_by_trial contains the target trial index by default.

Differential Revision: D67875128

Author: sdaulton

ax/modelbridge/transforms/tests/test_transform_to_new_sq.py

@@ -70,11 +70,14 @@ def setUp(self) -> None:
         t.mark_completed()
         self.data = self.exp.fetch_data()
 
+        self._refresh_modelbridge()
+
+    def _refresh_modelbridge(self) -> None:
         self.modelbridge = ModelBridge(
             search_space=self.exp.search_space,
             model=Model(),
             experiment=self.exp,
-            data=self.data,
+            data=self.exp.lookup_data(),
             status_quo_name="status_quo",
         )
 
@@ -141,16 +144,18 @@ def test_single_trial_is_not_transformed(self) -> None:
         obs2 = tf.transform_observations(obs)
         self.assertEqual(obs, obs2)
 
-    def test_taget_trial_index(self) -> None:
+    def test_target_trial_index(self) -> None:
         sobol = get_sobol(search_space=self.exp.search_space)
-        self.exp.new_batch_trial(generator_run=sobol.gen(2))
+        self.exp.new_batch_trial(generator_run=sobol.gen(2), optimize_for_power=True)
         t = self.exp.trials[1]
         t = assert_is_instance(t, BatchTrial)
         t.mark_running(no_runner_required=True)
         self.exp.attach_data(
             get_branin_data_batch(batch=assert_is_instance(t, BatchTrial))
         )
 
+        self._refresh_modelbridge()
+
         observations = observations_from_data(
             experiment=self.exp,
             data=self.exp.lookup_data(),
@@ -166,12 +171,12 @@ def test_taget_trial_index(self) -> None:
 
         with mock.patch(
             "ax.modelbridge.transforms.transform_to_new_sq.get_target_trial_index",
-            return_value=10,
+            return_value=0,
         ):
             t = TransformToNewSQ(
                 search_space=self.exp.search_space,
                 observations=observations,
                 modelbridge=self.modelbridge,
             )
 
-        self.assertEqual(t.default_trial_idx, 10)
+        self.assertEqual(t.default_trial_idx, 0)

ax/modelbridge/transforms/transform_to_new_sq.py

@@ -73,6 +73,9 @@ def __init__(
             target_trial_index = get_target_trial_index(
                 experiment=modelbridge._experiment
             )
+            trials_indices_with_sq_data = self.status_quo_data_by_trial.keys()
+            if target_trial_index not in trials_indices_with_sq_data:
+                target_trial_index = max(trials_indices_with_sq_data)
 
         if target_trial_index is not None:
             self.default_trial_idx: int = assert_is_instance(