Fixed #842 Incorrect Post-Processing in Naive mass_PI (#886)

* fix mass_PI

* removed unnecessary blank line

Author: NimaSarajpoor

tests/naive.py

@@ -145,19 +145,20 @@ def mass_PI(
     T_subseq_isconstant = rolling_isconstant(T, m, T_subseq_isconstant)
 
     D = distance_profile(Q, T, m)
+    D[np.isnan(D)] = np.inf
     for i in range(len(T) - m + 1):
-        if Q_subseq_isconstant and T_subseq_isconstant[i]:
-            D[i] = 0
-        elif Q_subseq_isconstant or T_subseq_isconstant[i]:
-            D[i] = np.sqrt(m)
-        else:  # pragma: no cover
-            pass
+        if np.isfinite(D[i]):
+            if Q_subseq_isconstant and T_subseq_isconstant[i]:
+                D[i] = 0
+            elif Q_subseq_isconstant or T_subseq_isconstant[i]:
+                D[i] = np.sqrt(m)
+            else:  # pragma: no cover
+                pass
 
     if ignore_trivial:
         apply_exclusion_zone(D, trivial_idx, excl_zone, np.inf)
         start = max(0, trivial_idx - excl_zone)
         stop = min(D.shape[0], trivial_idx + excl_zone + 1)
-    D[np.isnan(D)] = np.inf
 
     I = np.argmin(D)
     P = D[I]