add unit test

Author: kbruegge

irf/tests/test_exposure_map.py

@@ -0,0 +1,36 @@
+import os
+import pytest
+import fact.io as fio
+import pandas as pd
+from irf import estimate_exposure_time
+
+
+FIXTURE_DIR = os.path.join(
+    os.path.dirname(os.path.realpath(__file__)),
+    'test_files',
+)
+
+
+@pytest.fixture
+def events():
+    return fio.read_data(os.path.join(FIXTURE_DIR, 'crab_dl3_sample.hdf5'), key='events')
+
+
+@pytest.fixture
+def runs():
+    return fio.read_data(os.path.join(FIXTURE_DIR, 'crab_dl3_sample.hdf5'), key='runs')
+
+
+
+def test_exposure_time(runs, events):
+        n_crab_sample = 687226
+        n_test_sample = len(events)
+
+        live_time_crab = runs.ontime.sum() / 3600  # to hours
+
+        expected_live_time_sample = n_test_sample / n_crab_sample * live_time_crab
+
+        timestamps = pd.to_datetime(events.timestamp).values
+        exposure = estimate_exposure_time(timestamps).to('h').value
+
+        assert expected_live_time_sample == pytest.approx(exposure, 0.05)