some od reading bugs

Author: CamDavidsonPilon

core/pioreactor/background_jobs/od_reading.py

@@ -476,7 +476,9 @@ def _sin_regression_with_known_freq(
         if SSE > 1e-20:
             AIC = n * np.log(SSE / n) + 2 * 3
         else:
-            AIC = math.inf
+            # Perfect (or numerically-perfect) fits should rank best when selecting
+            # between candidate AC frequencies.
+            AIC = -math.inf
 
         if np.sqrt(b**2 + c**2) <= 1e-20:
             A = 0
@@ -1319,10 +1321,20 @@ def _determine_best_ir_led_intensity(
 
         _, REF_on_signal = on_reading.popitem()
 
-        ir_intensity_argmax_REF_can_be = initial_ir_intensity / REF_on_signal.reading * 0.250
+        def _safe_ratio(numerator: float, denominator: float) -> float:
+            # Very small / zero sensor values can occur during startup or hardware faults.
+            # Treating the ratio as +inf preserves current behavior (falls back to MAX)
+            # while avoiding runtime crashes.
+            if denominator <= 0.0:
+                return float("inf")
+            return numerator / denominator
+
+        ir_intensity_argmax_REF_can_be = _safe_ratio(initial_ir_intensity, REF_on_signal.reading) * 0.250
 
         # divide by N since the culture is unlikely to Nx.
-        ir_intensity_argmax_ANGLE_can_be = (initial_ir_intensity / culture_on_signal.reading) * 3.0 / 50
+        ir_intensity_argmax_ANGLE_can_be = (
+            _safe_ratio(initial_ir_intensity, culture_on_signal.reading) * 3.0 / 50
+        )
 
         ir_led_intensity = min(
             MAX, ir_intensity_argmax_ANGLE_can_be, ir_intensity_argmax_REF_can_be
@@ -1496,10 +1508,12 @@ def stop_ir_led(self) -> None:
     ############
 
     def on_sleeping(self) -> None:
-        self.record_from_adc_timer.pause()
+        if hasattr(self, "record_from_adc_timer"):
+            self.record_from_adc_timer.pause()
 
     def on_sleeping_to_ready(self) -> None:
-        self.record_from_adc_timer.unpause()
+        if hasattr(self, "record_from_adc_timer"):
+            self.record_from_adc_timer.unpause()
 
     def on_disconnected(self) -> None:
         try:

core/tests/test_od_reading.py

@@ -685,6 +685,18 @@ def test_ADC_picks_to_correct_freq_even_if_slight_noise_in_freq() -> None:
     assert best_freq == actual_freq
 
 
+def test_ADC_picks_exact_frequency_for_perfect_signal() -> None:
+    actual_freq = 50.0
+    # Use a non-aliased sample grid so the linear solve is non-singular.
+    x = [i / 29 for i in range(29)]
+    y = [10.0 + np.sin(actual_freq * 2 * np.pi * _x + 0.3) for _x in x]
+
+    adc_reader = ADCReader(channels=["1"])
+
+    best_freq = adc_reader.determine_most_appropriate_AC_hz({"1": x}, {"1": y})
+    assert best_freq == actual_freq
+
+
 def test_error_thrown_if_wrong_angle() -> None:
     with pytest.raises(ValueError):
         start_od_reading(make_channels("100", "135"), fake_data=True, experiment="test_error_thrown_if_wrong_angle")  # type: ignore
@@ -736,7 +748,7 @@ def test_sin_regression_all_negative() -> None:
 
     (C, A, phi), AIC = adc_reader._sin_regression_with_known_freq(x, y, freq)
     assert C == -2
-    assert AIC == float("inf")
+    assert AIC == -float("inf")
 
 
 @pytest.mark.slow
@@ -915,6 +927,8 @@ def test_outliers_are_removed_in_sin_regression() -> None:
 def test_interval_is_empty() -> None:
     with start_od_reading(make_channels("90", "REF"), interval=None, fake_data=True) as od:
         assert not hasattr(od, "record_from_adc_timer")
+        od.on_sleeping()
+        od.on_sleeping_to_ready()
 
 
 def test_determine_best_ir_led_intensity_values() -> None:
@@ -950,6 +964,16 @@ def test_determine_best_ir_led_intensity_values() -> None:
         == 50  # 6.0
     )
 
+    assert (
+        _determine_best_ir_led_intensity(
+            {"2": "90"},
+            50,
+            {"1": structs.RawPDReading(0.0, "1"), "2": structs.RawPDReading(0.0, "2")},
+            {"1": structs.RawPDReading(0.001, "1"), "2": structs.RawPDReading(0.001, "2")},
+        )
+        == 85.0
+    )
+
 
 def test_calibration_not_requested() -> None:
     with start_od_reading(make_channels("90", "REF"), interval=None, fake_data=True, calibration=False) as od: