removed lp

Author: PhilippSchmelter

src/markov/transitions.py

@@ -1,15 +1,19 @@
 import numpy as np
 import pandas as pd
 
-from src.config import CONFIG
-
 from ._core import _transition_counts
 
-alpha = float(CONFIG["model"]["laplace_alpha"])
-
 
 def build_transition_matrices(df: pd.DataFrame, *, dtype=np.float32) -> np.ndarray:
     counts = _transition_counts(df, dtype=dtype)
-    counts += alpha
-    counts /= counts.sum(axis=2, keepdims=True)
-    return counts.astype(dtype)
+    row_sum = counts.sum(axis=2, keepdims=True)
+    empty = row_sum == 0
+    if np.any(empty):
+        n_states = counts.shape[2]
+        idx_b, idx_i, _ = np.where(empty)
+        counts[idx_b, idx_i, :] = 0
+        counts[idx_b, idx_i, idx_i] = 1
+    row_sum[empty] = 1
+    probs = counts / row_sum
+
+    return probs.astype(dtype)