Remove hardcoded threshold; subtract reference implant weight from re…

…ference weight pct calculation

alyx/actions/water_control.py

@@ -352,7 +352,11 @@ def expected_weight(self, date=None):
             return 0
         pz = self.zscore_weight_pct / pct_sum
         pr = self.reference_weight_pct / pct_sum
-        return pz * self.zscore_weight(date=date) + pr * self.reference_weight(date=date)
+        ref_weight = self.reference_weight(date=date)
+        ref_iw = self.reference_implant_weight_at(date) or 0.
+        iw = self.last_implant_weight_before(date) or 0.
+        ref_pct = pr * (ref_weight - ref_iw) + iw
+        return pz * self.zscore_weight(date=date) + ref_pct
 
     def percentage_weight(self, date=None):
         """Percentage of the weight relative to the expected weight.
@@ -414,7 +418,10 @@ def expected_water(self, date=None):
         weight = self.last_weighing_before(date=date)
         weight = weight[1] if weight else 0.
         expected_weight = self.expected_weight(date=date) or 0.
-        return 0.05 * (weight - iw) if weight < 0.8 * expected_weight else 0.04 * (weight - iw)
+        pct_sum = (self.reference_weight_pct + self.zscore_weight_pct)
+        # Increase required water by 0.01mL/g if weight below pct reference
+        pct_weight = (pct_sum * expected_weight)
+        return 0.05 * (weight - iw) if weight < pct_weight else 0.04 * (weight - iw)
 
     def given_water(self, date=None, has_session=None):
         """Return the amount of water given at a specified date."""

alyx/alyx/settings_lab_template.py

@@ -3,7 +3,7 @@
 # ALYX-SPECIFIC
 ALLOWED_HOSTS = ['localhost', '127.0.0.1']
 LANGUAGE_CODE = 'en-us'
-TIME_ZONE = 'Europe/London'
+TIME_ZONE = 'Europe/London'  # NB: Changing the timezone here requires migrations
 GLOBUS_CLIENT_ID = '525cc543-8ccb-4d11-8036-af332da5eafd'
 SUBJECT_REQUEST_EMAIL_FROM = '[email protected]'
 DEFAULT_SOURCE = 'IBL'