clean up some edge cases

CHANGELOG.md

@@ -3,8 +3,9 @@
  - The "Label" step in the New Experiment flow is skipped if there is only 1 active Pioreactor in the cluster.
  - Silenced the "LED is locked" warning - now it's a DEBUG level message.
  - Fixed bug that wasn't passing lists correctly  in `TopicToParserToTable`
- - Faster boot times
- - Fixed a bug where a plugin would not be loaded if it's name collided with a module in the stdlib. For example, putting `test.py` in `.pioreactor/plugins` would not be loaded, since when we tried to import `test`, it would load the stdlib's `test`, not ours. This has been fixed.
+ - Faster boot times.
+ - Faster UI load times.
+ - Fixed a bug where a plugin would not be loaded if it's name collided with a module in the stdlib. For example, putting `test.py` in `.pioreactor/plugins` would not be loaded, since when we tried to import`test`, it would load the stdlib's `test`, not the local plugin. This has been fixed.
  - Simplify some UI elements.
  - Security improvements.
 

pioreactor/actions/stirring_calibration.py

@@ -87,6 +87,13 @@ def stirring_calibration(min_dc: int, max_dc: int) -> None:
             logger.error("No RPMs were measured. Is the stirring spinning?")
             return
 
+        if len(filtered_dcs) <= n_samples * 0.75:
+            # the above can fail if all measured rpms are 0
+            logger.warning(
+                "Not enough RPMs were measured. Is the stirring spinning and working correctly? Try changing your initial_duty_cycle."
+            )
+            return
+
         # since in practice, we want a look up from RPM -> required DC, we
         # set x=measure_rpms, y=dcs
         (rpm_coef, rpm_coef_std), (intercept, intercept_std) = simple_linear_regression(
@@ -100,7 +107,7 @@ def stirring_calibration(min_dc: int, max_dc: int) -> None:
             )
             return
 
-        if intercept <= 0:
+        elif intercept <= 0:
             logger.warning("Something went wrong - the intercept should be greater than 0.")
             return
 

pioreactor/background_jobs/stirring.py

@@ -314,7 +314,9 @@ def kick_stirring(self) -> None:
         self.logger.debug("Kicking stirring")
         self.set_duty_cycle(100)
         sleep(0.20)
-        self.set_duty_cycle(1.01 * self._previous_duty_cycle)
+        self.set_duty_cycle(
+            max(1.01 * self._previous_duty_cycle, 60)
+        )  # DC should never be above 60. We want to avoid the death spiral to 100%.
 
     def kick_stirring_but_avoid_od_reading(self) -> None:
         """

pioreactor/utils/math_helpers.py

@@ -99,6 +99,10 @@ def residuals_of_simple_linear_regression(x: Sequence, y: Sequence, trimmed=Fals
 
 
 def correlation(x: Sequence, y: Sequence) -> float:
-    from statistics import correlation
+    from statistics import correlation, StatisticsError
 
-    return correlation(x, y)
+    try:
+        return correlation(x, y)
+    except StatisticsError as e:
+        # Raising the original error with additional data
+        raise StatisticsError(f"{e}. x: {x}, y: {y}") from e