diff --git a/src/dartsort/cluster/gaussian_mixture.py b/src/dartsort/cluster/gaussian_mixture.py
index f7f15a4e..f3a46119 100644
--- a/src/dartsort/cluster/gaussian_mixture.py
+++ b/src/dartsort/cluster/gaussian_mixture.py
@@ -249,16 +249,16 @@ def m_step(self, likelihoods=None, show_progress=False, prev_means=None):
             for j, unit in enumerate(zip(unit_ids, results)):
                 assert unit.annotations["unit_id"] == j
                 self.units.append(unit)
-        if self.log_proportions is not None:
-            # this is the index of the noise unit. it's got to be larger than
-            # the largest unit index
-            maxix = self.log_proportions.numel() - 1
-            assert (unit_ids < maxix).all()
-            ixs = torch.cat((unit_ids, torch.tensor([maxix])))
-            self.log_proportions = self.log_proportions[ixs]
+        # if self.log_proportions is not None:
+        #     # this is the index of the noise unit. it's got to be larger than
+        #     # the largest unit index
+        #     maxix = self.log_proportions.numel() - 1
+        #     assert (unit_ids < maxix).all()
+        #     ixs = torch.cat((unit_ids, torch.tensor([maxix])))
+        #     self.log_proportions = self.log_proportions[ixs]
         if prev_means is not None:
             nu = len(unit_ids)
-            prev_means = prev_means[unit_ids]
+            # prev_means = prev_means[unit_ids]
             new_means, *_ = self.stack_units(mean_only=True)
             dmu = (prev_means - new_means).abs_().view(nu, -1)
             adif = torch.max(dmu)
@@ -1091,19 +1091,32 @@ def unit_group_criterion(
 
         if fit_type == "refit_all":
             units = []
-            subunit_logliks = spikes_core.features.new_full((len(unit_ids), len(in_any)), -torch.inf)
+            subunit_logliks = spikes_core.features.new_full(
+                (len(unit_ids), len(in_any)), -torch.inf
+            )
             full_loglik = 0.0
             for i, k in enumerate(unit_ids):
-                u = self.fit_unit(unit_id=k, indices=in_any, likelihoods=likelihoods, features=spikes_extract)
+                u = self.fit_unit(
+                    unit_id=k,
+                    indices=in_any,
+                    likelihoods=likelihoods,
+                    features=spikes_extract,
+                )
                 units.append(u)
-                _, subunit_logliks[i] = self.unit_log_likelihoods(unit=u, spikes=spikes_core)
+                _, subunit_logliks[i] = self.unit_log_likelihoods(
+                    unit=u, spikes=spikes_core
+                )
             subunit_log_props = F.softmax(subunit_logliks, dim=0).mean(1).log_()
             # loglik per spik
-            full_loglik = torch.logsumexp(subunit_logliks.T + subunit_log_props, dim=1).mean()
+            full_loglik = torch.logsumexp(
+                subunit_logliks.T + subunit_log_props, dim=1
+            ).mean()
             unit = self.fit_unit(indices=in_any, features=spikes_extract)
             likelihoods = None
         elif fit_type == "avg_preexisting":
-            unit = self.units[unit_ids[0]].avg_with(*[self.units[u] for u in unit_ids[1:]])
+            unit = self.units[unit_ids[0]].avg_with(
+                *[self.units[u] for u in unit_ids[1:]]
+            )
             if debug:
                 subunit_logliks = likelihoods[:, in_any][unit_ids]
             full_loglik = marginal_loglik(
@@ -1377,8 +1390,13 @@ def avg_with(self, *others):
             n_channels=self.n_channels,
             noise=self.noise,
         )
-        new.register_buffer("mean", (self.mean + sum(o.mean for o in others)) / (1 + len(others)))
-        new.register_buffer("channels", torch.cat([self.channels, *[o.channels for o in others]]).unique())
+        new.register_buffer(
+            "mean", (self.mean + sum(o.mean for o in others)) / (1 + len(others))
+        )
+        new.register_buffer(
+            "channels",
+            torch.cat([self.channels, *[o.channels for o in others]]).unique(),
+        )
         assert self.cov_kind == "zero"
         return new
 
@@ -1726,7 +1744,9 @@ def coo_to_scipy(coo_tensor):
     return coo_array((data, coords), shape=coo_tensor.shape)
 
 
-def marginal_loglik(indices, log_proportions, log_likelihoods, unit_ids=None, reduce="mean"):
+def marginal_loglik(
+    indices, log_proportions, log_likelihoods, unit_ids=None, reduce="mean"
+):
     if unit_ids is not None:
         # renormalize log props
         log_proportions = log_proportions[unit_ids]