diff --git a/src/elexsolver/EITransitionSolver.py b/src/elexsolver/EITransitionSolver.py
index 992aa371..7b7fa814 100644
--- a/src/elexsolver/EITransitionSolver.py
+++ b/src/elexsolver/EITransitionSolver.py
@@ -38,22 +38,38 @@ def mean_absolute_error(self, X, Y):
         # return mae
         return 0 # TODO
 
+    def _check_and_rescale(self, A):
+        if not np.all(A.sum(axis=0) == 1):
+            LOG.warn("Each column (unit) needs to sum to 1.  Rescaling...")
+            if isinstance(A, np.ndarray):
+                for j in range(0, A.shape[1]):
+                    A[:, j] /= A[:, j].sum()
+            else:
+                # pandas.DataFrame()
+                for col in A.columns:
+                    A[col] /= A[col].sum()
+        return A
+
     def fit_predict(self, X, Y):
         self._check_any_element_nan_or_inf(X)
         self._check_any_element_nan_or_inf(Y)
         self._check_percentages(X)
         self._check_percentages(Y)
 
-        # TODO: check if these matrices are (long x short), then transpose
-        # currently assuming this is the case since the other solver expects (long x short)
-        X = np.transpose(X)
-        Y = np.transpose(Y)
+        # matrices should be (things x units), where the number of units is > the number of things
+        if X.shape[0] > X.shape[1]:
+            X = X.T
+        if Y.shape[0] > Y.shape[1]:
+            Y = Y.T
 
         if X.shape[1] != Y.shape[1]:
             raise ValueError(f"Number of units in X ({X.shape[1]}) != number of units in Y ({Y.shape[1]}).")
         if Y.shape[1] != len(self._n):
             raise ValueError(f"Number of units in Y ({Y.shape[1]}) != number of units in n ({len(self._n)}).")
 
+        X = self._check_and_rescale(X)
+        Y = self._check_and_rescale(Y)
+
         num_units = len(self._n) # should be the same as the number of units in Y
         num_rows = X.shape[0]    # number of things in X that are being transitioned "from"
         num_cols = Y.shape[0]    # number of things in Y that are being transitioned "to"
@@ -77,8 +93,11 @@ def fit_predict(self, X, Y):
                 observed=Y_obs,
                 shape=(num_units, num_cols),
             )
-            # TODO: allow other samplers; this one is very good but slow
-            model_trace = pm.sample(chains=self._chains)
+            try:
+                # TODO: allow other samplers; this one is very good but slow
+                model_trace = pm.sample(chains=self._chains)
+            except:
+                print(model.debug())
 
         b_values = np.transpose(
             model_trace["posterior"]["beta"].stack(all_draws=["chain", "draw"]).values, axes=(3, 0, 1, 2))