app: stacked_cores: try varying the number of control loops separately from the coupling loops

doesn't make a huge difference, apparently.

crates/applications/stacked_cores/scripts/inverter_characteristics.py

@@ -125,6 +125,13 @@ class Piecewise:
     def slope_df(self, from_: float = 0.0, to: float = 1.0, points: int = 101) -> DataFrame:
         return self.df_for(from_, to, points, self.get_slope)
 
+    def min_max_slope(self):
+        slope = [self.get_slope(0.01*x) for x in range(101)]
+        return min(slope), max(slope)
+
+    def max_abs_slope(self) -> float:
+        return max(abs(s) for s in self.min_max_slope())
+
     def plot_for(self, from_: float, to: float, title: str, f):
         df = self.df_for(from_, to, points=101, f=f)
         fig = px.line(df, x="x", y="y", title=title)

crates/applications/stacked_cores/scripts/plot_inverters.py

@@ -118,12 +118,14 @@ of_interest += [(p, get_meas(p)) for p in
 
 
 # plot all viable inverters
-# of_interest += filter_meas(run="41", rad_um=400, viable_inverter=True)
+of_interest += filter_meas(run="41", viable_inverter=True)
 # of_interest += filter_meas(run="42", rad_um=400, couplings=4)
 # of_interest += filter_meas(run="42", rad_um=400, couplings=9)
 # of_interest += filter_meas(run="42", rad_um=400, couplings=2)
 # of_interest += filter_meas(run="42", rad_um=400, couplings=6)
-of_interest += filter_meas(run="43")
+# of_interest += filter_meas(run="43")
+
+of_interest.sort(key=lambda i: -i[1].max_abs_slope())
 
 for (params, curve) in of_interest:
     if not params.is_inverter:

crates/applications/stacked_cores/scripts/stacked_cores_40xx_db.py

@@ -72,6 +72,11 @@ class SimParams:
         )
         return self.tuple == match_tuple
 
+    def ensure_inverter(self, curve):
+        if not self.is_inverter:
+            return curve.logically_inverted()
+        return curve
+
 class SimParams40(SimParams):
     @property
     def run(self) -> str:
@@ -260,7 +265,7 @@ def filter_meas(run: str = None, rad_um: int = None, drive: float = None, coupli
                 if p.matches(run, rad_um, drive, couplings, wrappings) \
                     and get_meas(p) \
                     and get_meas(p).num_pieces > 0 \
-                    and matches(get_meas(p).logically_inverted().is_viable_inverter(), viable_inverter)
+                    and matches(p.ensure_inverter(get_meas(p)).is_viable_inverter(), viable_inverter)
         ],
         key = lambda v: v[0].tuple
     )