From f246c88dd690eaa5d7db1e59e6828a271ba717f8 Mon Sep 17 00:00:00 2001
From: Junzi Sun <junzisun@gmail.com>
Date: Wed, 4 Apr 2018 16:41:34 +0200
Subject: [PATCH] add try except

---
 pyModeS/decoder/bds/__init__.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/pyModeS/decoder/bds/__init__.py b/pyModeS/decoder/bds/__init__.py
index 257debd..fffa1b9 100644
--- a/pyModeS/decoder/bds/__init__.py
+++ b/pyModeS/decoder/bds/__init__.py
@@ -80,8 +80,11 @@ def is50or60(msg, spd_ref, trk_ref, alt_ref):
 
     # since the covariance matrix is identity matrix,
     #     M-dist is same as eculidian distance
-    dist = np.linalg.norm(X-Mu, axis=1)
-    BDS = allbds[np.nanargmin(dist)]
+    try:
+        dist = np.linalg.norm(X-Mu, axis=1)
+        BDS = allbds[np.nanargmin(dist)]
+    except ValueError:
+        return None
 
     return BDS