Resolve "(BalancingLearner) loss is cached incorrectly"

Closes #108 (closed)

adaptive/learner/balancing_learner.py

@@ -56,6 +56,7 @@ class BalancingLearner(BaseLearner):
 
         self._points = {}
         self._loss = {}
+        self._pending_loss = {}
         self._cdims_default = cdims
 
         if len(set(learner.__class__ for learner in self.learners)) > 1:
@@ -95,6 +96,7 @@ class BalancingLearner(BaseLearner):
         index, x = x
         self._points.pop(index, None)
         self._loss.pop(index, None)
+        self._pending_loss.pop(index, None)
         self.learners[index].tell(x, y)
 
     def tell_pending(self, x):
@@ -103,13 +105,19 @@ class BalancingLearner(BaseLearner):
         self._loss.pop(index, None)
         self.learners[index].tell_pending(x)
 
-    def loss(self, real=True):
+    def losses(self, real=True):
         losses = []
+        loss_dict = self._loss if real else self._pending_loss
+
         for index, learner in enumerate(self.learners):
-            if index not in self._loss:
-                self._loss[index] = learner.loss(real)
-            loss = self._loss[index]
-            losses.append(loss)
+            if index not in loss_dict:
+                loss_dict[index] = learner.loss(real)
+            losses.append(loss_dict[index])
+
+        return losses        
+
+    def loss(self, real=True):
+        losses = self.losses(real)
         return max(losses)
 
     def plot(self, cdims=None, plotter=None):