add error raise for NaN data

seispy/data/cmpVsVp.txt

+2.536	13.078
+2.497	22.939
+2.461	38.109
+2.418	54.500
+2.366	70.908
+2.311	93.117
+2.249	117.973
+2.206	137.187
+2.180	155.512
+2.124	178.782
+2.068	191.306
+2.013	207.872
+1.958	219.143
+1.919	231.666
+1.870	244.174
+1.831	252.290
+1.782	263.561
+1.736	274.832
+1.684	288.750
+1.637	305.157
+1.598	321.723
+1.549	336.719
+1.498	357.343
+1.464	369.692
+1.435	382.199
+1.399	396.133
+1.373	414.110
+1.344	434.734
+1.318	451.474
+1.291	472.272
+1.266	490.423
+1.243	509.984
+1.224	533.430
+1.197	558.620
+1.188	585.220
+1.164	604.781
+1.145	625.580
+1.136	646.552
+1.136	665.940
+1.145	690.796
+1.156	726.812

seispy/rf.py

@@ -319,8 +319,14 @@ class RF(object):
     
     def detrend(self):
         self.logger.RFlog.info('Detrend all data')
-        for _, row in self.eqs.iterrows():
-            row['data'].detrend()
+        drop_idx = []
+        for i, row in self.eqs.iterrows():
+            try:
+                row['data'].detrend()
+            except:
+                self.logger.RFlog.error('Data error in {}'.format(row['date'].strftime('%Y.%j.%H.%M.%S')))
+                drop_idx.append(i)
+        self.eqs.drop(drop_idx, inplace=True)
 
     def filter(self, freqmin=None, freqmax=None, order=4):
         if freqmin is None:

setup.py

@@ -6,7 +6,7 @@ with open("README.md", "r") as fh:
     long_description = fh.read()
 
 
-VERSION = "1.2.7"
+VERSION = "1.2.8"
 setup(name='python-seispy',
       version=VERSION,
       author='Mijian Xu',