From e6b0c2b470860182f7ff7812764c2ba286b90c65 Mon Sep 17 00:00:00 2001
From: Sebastian Wehling-Benatelli <sebastian.wehling@rub.de>
Date: Wed, 10 Jun 2015 15:37:58 +0200
Subject: [PATCH] zero xings are now be derived from demeaned data

---
 pylot/core/pick/utils.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pylot/core/pick/utils.py b/pylot/core/pick/utils.py
index b3d3656b..e3fb6eca 100644
--- a/pylot/core/pick/utils.py
+++ b/pylot/core/pick/utils.py
@@ -67,7 +67,9 @@ def earllatepicker(X, nfac, TSNR, Pick1, iplot=None):
     #get earliest possible pick
 
     #determine all zero crossings in signal window
-    zc = crossings_nonzero_all(x[isignal])
+    # remove mean from signal window
+    signal = x[isignal] - x[isignal].mean()
+    zc = crossings_nonzero_all(signal)
     #calculate mean half period T0 of signal as the average of the
     T0 = np.mean(np.diff(zc)) * X[0].stats.delta  #this is half wave length!
     #T0/4 is assumed as time difference between most likely and earliest possible pick!