fix bugs in back azimuth calculation

Author: wjlei1990

docs/source/tutorial.rst

@@ -1,5 +1,67 @@
 Tutorial
-*******************
+========
 
-This is tutorial...To be continued...
+The data used here should be read in by `obspy`_ as a ``Stream`` or ``Trace``.
 
+.. _obspy: https://github.com/obspy/obspy/wiki 
+
+1. Signal processing
+--------------------
+
+Give observed seismograms, you want to apply signal processing operations to remove the instrument response(stationxml file is required), filter to a certain band, re-sampling and rotate from ``NE`` to ``RT``. You can write your script this way::
+
+  from pytomo3d.signal.process import process 
+  from obspy import read, read_inventory
+
+  # read in waveform data
+  obs = read("II.AAK.obs.mseed")
+  # read in stationxml
+  inv = read_inventory("II.AAK.xml")
+  # set up your filter frequency band
+  pre_filt = [1/150., 1/100., 1/50., 1/40.]
+  # setup cutting starttime and endtime
+  starttime = stream[0].stats.starttime + 10 # second
+  endtime = stream[0].stats.starttime + 3610 # second
+  new_obs = process(obs, remove_response_flag=True, inventory=inv,
+                    filter_flag=True, pre_filt=pre_filt,
+                    starttime=starttime, endtime=endtime, 
+                    resample_flag=True, sampling_rate=1.0,
+                    rotate_flag=True, event_latitude=12.2,
+                    event_longitude=-95.6)
+  # write out processed stream
+  new_obs.write("II.AAK.obs.proc.mseed", format="MSEED")
+
+Given an synthetic stream, you want to filter, re-sample and rotate::
+
+  new_syn = process(syn, remove_response_flag=False, inventory=inv,
+                    filter_flag=True, pre_filt=pre_filt,
+                    starttime=starttime, endtime=endtime, 
+                    resample_flag=True, sampling_rate=1.0,
+                    rotate_flag=True, event_latitude=12.2,
+                    event_longitude=-95.6)
+  # write out processed stream
+  new_obs.write("II.AAK.syn.proc.mseed", format="MSEED")
+
+2. Window Selection
+-------------------
+To make window selections, you need first prepare window selection config dictionary in python::
+
+  {
+    "Z": pyflex.Config,
+    "R": pyflex.Config,
+    "T": pyflex.Config
+  }
+
+And the selection script::
+
+  window = window_on_stream(
+      obsd, synt, config_dict, station=inv, event=event, figure_mode=True,
+      figure_dir="./figure/", verbose=False)
+
+3. Adjoint Sources
+------------------
+For adjoint source calculate, the script::
+
+  adjsrcs = calcualte_adjsrc_on_stream(
+      obsd, synt, windows, config, 'multitaper_misfit',
+      figure_mode=True, figure_dir="./figure")

pytomo3d/adjoint/adjsrc.py

@@ -200,7 +200,7 @@ def calculate_baz(elat, elon, slat, slon):
     :return: back azimuth
     """
 
-    _, baz, _ = gps2DistAzimuth(elat, elon, slat, slon)
+    _, _, baz = gps2DistAzimuth(elat, elon, slat, slon)
 
     return baz
 

pytomo3d/signal/rotate.py

@@ -315,8 +315,8 @@ def rotate_stream(st, event_latitude, event_longitude,
         raise ValueError("Mode %s required inventory(stationxml) "
                          "information provided" % mode)
 
-    _, baz, _ = gps2DistAzimuth(station_latitude, station_longitude,
-                                event_latitude, event_longitude)
+    _, _, baz = gps2DistAzimuth(event_latitude, event_longitude,
+                                station_latitude, station_longitude)
 
     components = [tr.stats.channel[-1] for tr in st]