Avoid state formula warning noise

changelog.d/7800.fixed.md

@@ -0,0 +1 @@
+Avoid formula warnings in North Carolina TANF, Pennsylvania TANF, and Vermont military retirement exemption calculations.

policyengine_us/tests/policy/baseline/gov/states/nc/ncdhhs/tanf/nc_tanf_income_eligible.yaml

@@ -35,3 +35,13 @@
     nc_tanf_household_size: 0
   output:
     nc_tanf_income_eligible: false
+
+- name: Demographically eligible household with 0 household size is still ineligible.
+  period: 2024
+  input:
+    state_code: NC
+    nc_tanf_reduced_need_standard: 72 * 12
+    nc_tanf_household_size: 0
+    nc_demographic_tanf_eligible: true
+  output:
+    nc_tanf_income_eligible: false

policyengine_us/variables/gov/states/nc/ncdhhs/tanf/nc_tanf_income_eligible.py

@@ -13,7 +13,12 @@ def formula(spm_unit, period, parameters):
         household_size = spm_unit("nc_tanf_household_size", period)
         reduced_need_standard = spm_unit("nc_tanf_reduced_need_standard", period)
 
-        need_standard_fraction = reduced_need_standard / household_size
+        need_standard_fraction = np.divide(
+            reduced_need_standard,
+            household_size,
+            out=np.zeros_like(reduced_need_standard, dtype=float),
+            where=household_size != 0,
+        )
         difference_threshold = (
             p.average_reduced_need_standard_threshold * MONTHS_IN_YEAR
         )

policyengine_us/variables/gov/states/pa/dhs/tanf/pa_tanf.py

@@ -28,7 +28,7 @@ def formula(spm_unit, period, parameters):
         gross_earned_income = add(spm_unit, period, ["tanf_gross_earned_income"])
         has_earned_income = gross_earned_income > 0
         wer_amount = where(
-            ~p.deduction_applies & has_earned_income,
+            (not p.deduction_applies) & has_earned_income,
             p.reimbursement,
             0,
         )

policyengine_us/variables/gov/states/vt/tax/income/adjusted_gross_income/subtractions/retirement_income_exemption/vt_military_retirement_income_based_exemption.py

@@ -48,13 +48,12 @@ def formula(tax_unit, period, parameters):
         agi_below_threshold = max_(p.partial_exemption_threshold - agi, 0)
 
         # Use mask to avoid division by zero
-        valid_threshold_difference = threshold_difference != 0
-        partial_exemption_amount = where(
-            valid_threshold_difference,
-            tax_unit_military_retirement_pay
-            * agi_below_threshold
-            / threshold_difference,
-            0,
+        valid_threshold_difference = thresholds_are_finite & (threshold_difference != 0)
+        partial_exemption_amount = np.divide(
+            tax_unit_military_retirement_pay * agi_below_threshold,
+            threshold_difference,
+            out=np.zeros_like(agi, dtype=float),
+            where=valid_threshold_difference,
         )
 
         # Calculate exemption amounts for each case