Added a test for negative intensity hazards

Author: spjuhel

climada/test/conftest.py

@@ -272,13 +272,19 @@ def _make_impf(
         hazard_type=HAZARD_TYPE,
         hazard_unit=HAZARD_UNIT,
         impf_id=IMPF_ID,
+        negative_intensities=False,
     ):
+        intensity = np.array([0, max_intensity / 2, max_intensity])
+        mdd = np.array([0, 0.5, 1])
+        if negative_intensities:
+            intensity = np.flip(intensity) * -1
+            mdd = np.flip(mdd)
         return ImpactFunc(
             haz_type=hazard_type,
             intensity_unit=hazard_unit,
             name=IMPF_NAME,
-            intensity=np.array([0, max_intensity / 2, max_intensity]),
-            mdd=np.array([0, 0.5, 1]),
+            intensity=intensity,
+            mdd=mdd,
             paa=np.array([1, 1, 1]) * paa_scale,
             id=impf_id,
         )
@@ -299,9 +305,19 @@ def _make_impfset(
         hazard_type=HAZARD_TYPE,
         hazard_unit=HAZARD_UNIT,
         impf_id=IMPF_ID,
+        negative_intensities=False,
     ):
         return ImpactFuncSet(
-            [impf_factory(paa_scale, max_intensity, hazard_type, hazard_unit, impf_id)]
+            [
+                impf_factory(
+                    paa_scale,
+                    max_intensity,
+                    hazard_type,
+                    hazard_unit,
+                    impf_id,
+                    negative_intensities,
+                )
+            ]
         )
 
     return _make_impfset

climada/test/test_trajectories.py

@@ -25,7 +25,13 @@
 
 from climada.engine.impact_calc import ImpactCalc
 from climada.entity.disc_rates.base import DiscRates
-from climada.test.conftest import CATEGORIES, EXPOSURE_REF_YEAR
+from climada.entity.impact_funcs.base import ImpactFunc
+from climada.entity.impact_funcs.impact_func_set import ImpactFuncSet
+from climada.test.conftest import (
+    CATEGORIES,
+    EXPOSURE_REF_YEAR,
+    hazard_intensity_factory,
+)
 from climada.trajectories import InterpolatedRiskTrajectory, StaticRiskTrajectory
 from climada.trajectories.constants import (
     AAI_METRIC_NAME,
@@ -70,6 +76,7 @@ def _make_snapshot(
         hazard_frequency_factor=1.0,
         paa_scale=1.0,
         group_id=None,
+        negative_intensities=False,
     ):
         exposures = exposures_factory(
             value_factor=exposure_value_factor, ref_year=date, group_id=group_id
@@ -82,6 +89,7 @@ def _make_snapshot(
 
         impfset = impfset_factory(
             paa_scale=paa_scale,
+            negative_intensities=negative_intensities,
         )
 
         return Snapshot(
@@ -474,6 +482,24 @@ def snapshot_future_interp_vulchange(snapshot_factory):
     )
 
 
+@pytest.fixture(scope="session")
+def snapshot_base_neg(snapshot_factory):
+    return snapshot_factory(
+        hazard_intensity_factor=-1.0,
+        negative_intensities=True,
+    )
+
+
+@pytest.fixture(scope="session")
+def snapshot_future_interp_neg(snapshot_factory):
+    return snapshot_factory(
+        date=2022,
+        exposure_value_factor=6.0,
+        hazard_intensity_factor=-2.0,
+        negative_intensities=True,
+    )
+
+
 @pytest.fixture(scope="session")
 def expected_interp_metrics():
     # fmt: off
@@ -752,6 +778,29 @@ def test_interpolated_trajectory(
     )
 
 
+def test_interpolated_trajectory_negative_intensities(
+    snapshot_base_neg,
+    snapshot_future_interp_neg,
+    expected_interp_metrics,
+    expected_period_metrics,
+):
+    interp_traj = InterpolatedRiskTrajectory(
+        [snapshot_base_neg, snapshot_future_interp_neg], return_periods=[50, 100, 250]
+    )
+    pd.testing.assert_frame_equal(
+        interp_traj.per_date_risk_metrics(),
+        expected_interp_metrics,
+        check_dtype=False,
+        check_categorical=False,
+    )
+    pd.testing.assert_frame_equal(
+        interp_traj.per_period_risk_metrics(),
+        expected_period_metrics,
+        check_dtype=False,
+        check_categorical=False,
+    )
+
+
 def test_interp_trajectory_with_group(
     snapshot_factory, expected_interp_metrics_wgroup, expected_interp_period_wgroup
 ):