From 1ceb347602a35e26ae29bf44ed53554d076925cb Mon Sep 17 00:00:00 2001
From: Darius Arnold <Darius.Arnold@ruhr-uni-bochum.de>
Date: Sat, 26 Aug 2017 17:26:35 +0200
Subject: [PATCH] [bugfix] avoid indexing an empty array when there are no NaNs
 at start of CF

---
 pylot/core/pick/charfuns.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pylot/core/pick/charfuns.py b/pylot/core/pick/charfuns.py
index 7cf16708..a6fb5841 100644
--- a/pylot/core/pick/charfuns.py
+++ b/pylot/core/pick/charfuns.py
@@ -299,8 +299,9 @@ class HOScf(CharacteristicFunction):
         # remove NaN's with first not-NaN-value,
         # so autopicker doesnt pick discontinuity at start of the trace
         ind = np.where(~np.isnan(LTA))[0]
-        first = ind[0]
-        LTA[:first] = LTA[first]
+        if ind.size:
+            first = ind[0]
+            LTA[:first] = LTA[first]
         self.cf = LTA
         self.xcf = x