Smarter handling of defaults

src/python_spectrometer/daq/settings.py

@@ -629,14 +629,17 @@ class DAQSettings(dict):
         # user-set fs or df take precedence over noverlap
         if 'fs' in self and 'df' in self:
             return ceil(self['fs'] / self['df'])
-        if 'n_pts' in self and 'n_seg' in self:
-            if 'noverlap' in self:
+        if 'n_pts' in self:
+            if 'noverlap' in self and 'n_seg' in self:
                 return int((self['n_pts'] + (self['n_seg'] - 1) * self['noverlap'])
                            / self['n_seg'])
             if default:
+                n_seg = self.get('n_seg', self.DEFAULT_N_SEG)
+                if 'noverlap' not in self:
                     a, b = self.DEFAULT_NOVERLAP_MAPPING
-                return ceil((self['n_pts'] + (self['n_seg'] - 1) * b)
-                            / (self['n_seg'] - (self['n_seg'] - 1) / a))
+                    return ceil((self['n_pts'] + (n_seg - 1) * b) / (n_seg - (n_seg - 1) / a))
+                return int((self['n_pts'] + (n_seg - 1) * self['noverlap']) / n_seg)
+
         # Could not infer from directly related quantities. Try with f_min/f_max and their defaults
         df = self.get('df', self.get('f_min', self.DEFAULT_DF if default else inf))
         fs = self.get('fs', self.get('f_max', self.DEFAULT_FS / 2 if default else inf) * 2)
@@ -662,12 +665,13 @@ class DAQSettings(dict):
         return None
 
     def _infer_n_seg(self, default: bool = False) -> int | None:
-        if nperseg is not None and not isinf(n_pts):
-            # Maximize n_seg using the largest possible noverlap
-            noverlap = self.get('noverlap',
-                                min(self._infer_noverlap() or inf, self._domain_noverlap.max()))
         nperseg = self.get('nperseg') or self._infer_nperseg()
         n_pts = self.get('n_pts') or self._infer_n_pts() or self._domain_n_pts.max()
+        noverlap = self.get('noverlap') or self._infer_noverlap()
+        if default and nperseg is not None and not isinf(n_pts):
+            a, b = self.DEFAULT_NOVERLAP_MAPPING
+            noverlap = noverlap or nperseg // a + b
+        if nperseg is not None and not isinf(n_pts) and noverlap is not None:
             return floor((n_pts - noverlap) / (nperseg - noverlap))
         if default:
             return self.DEFAULT_N_SEG