Merge pull request #1543 from chad-iris/fix-irisws-distaz

Fix irisws-distaz client following service upgrade to 1.0.3

obspy/clients/iris/client.py

@@ -15,8 +15,8 @@
 from future.utils import native_str
 
 import io
-import json
 import platform
+from lxml import objectify
 
 with standard_library.hooks():
     import urllib.parse
@@ -73,11 +73,11 @@ class Client(object):
     >>> result = client.distaz(stalat=1.1, stalon=1.2, evtlat=3.2,
     ...                        evtlon=1.4)
     >>> print(result['distance'])
-    2.09554
+    2.10256
     >>> print(result['backazimuth'])
-    5.46946
+    5.46944
     >>> print(result['azimuth'])
-    185.47692
+    185.47695
     """
     def __init__(self, base_url="http://service.iris.edu/irisws",
                  user="", password="", timeout=20, debug=False,
@@ -558,7 +558,7 @@ def sacpz(self, network, station, location="*", channel="*",
     def distaz(self, stalat, stalon, evtlat, evtlon):
         """
         Low-level interface for `distaz` Web service of IRIS
-        (http://service.iris.edu/irisws/distaz/) - release 1.0.1 (2010).
+        (http://service.iris.edu/irisws/distaz/) - release 1.0.3 (2016).
 
         This method will calculate the great-circle angular distance, azimuth,
         and backazimuth between two geographic coordinate pairs. All results
@@ -577,40 +577,47 @@ def distaz(self, stalat, stalon, evtlat, evtlon):
         :return: Dictionary containing values for azimuth, backazimuth and
             distance.
 
-        The azimuth is the angle from the station to the event, while the
-        backazimuth is the angle from the event to the station.
+        The ``azimuth`` is the angle from the station to the event, while the
+        ``backazimuth`` is the angle from the event to the station.
 
         Latitudes are converted to geocentric latitudes using the WGS84
         spheroid to correct for ellipticity.
 
+        The ``distance`` (in degrees) and ``distancemeters`` are the distance
+        between the two points on the spheroid.
+
         .. rubric:: Example
 
         >>> from obspy.clients.iris import Client
         >>> client = Client()
         >>> result = client.distaz(stalat=1.1, stalon=1.2, evtlat=3.2,
         ...                        evtlon=1.4)
         >>> print(result['distance'])
-        2.09554
+        2.10256
+        >>> print(result['distancemeters'])
+        233272.79028
         >>> print(result['backazimuth'])
-        5.46946
+        5.46944
         >>> print(result['azimuth'])
-        185.47692
+        185.47695
+        >>> print(result['ellipsoidname'])
+        WGS84
         """
-        # set JSON as expected content type
-        headers = {'Accept': 'application/json'}
         # build up query
         try:
-            data = self._fetch("distaz", headers=headers, stalat=stalat,
-                               stalon=stalon, evtlat=evtlat, evtlon=evtlon)
+            data = self._fetch("distaz", stalat=stalat, stalon=stalon,
+                               evtlat=evtlat, evtlon=evtlon)
         except urllib.request.HTTPError as e:
             msg = "No response data available (%s: %s)"
             msg = msg % (e.__class__.__name__, e)
             raise Exception(msg)
-        data = json.loads(data.decode())
+        data = objectify.fromstring(data.decode())
         results = {}
-        results['distance'] = data['distance']
-        results['backazimuth'] = data['backAzimuth']
-        results['azimuth'] = data['azimuth']
+        results['ellipsoidname'] = data.ellipsoid.attrib['name']
+        results['distance'] = data.distance
+        results['distancemeters'] = data.distanceMeters
+        results['backazimuth'] = data.backAzimuth
+        results['azimuth'] = data.azimuth
         return results
 
     def flinnengdahl(self, lat, lon, rtype="both"):
@@ -769,7 +776,7 @@ def traveltime(self, model='iasp91', phases=DEFAULT_PHASES, evdepth=0.0,
         Distance   Depth   Phase   Travel    Ray Param  Takeoff  Incident ...
           (deg)     (km)   Name    Time (s)  p (s/deg)   (deg)    (deg)   ...
         ------------------------------------------------------------------...
-            3.24    22.9   P         49.39    13.749     53.77    45.82   ...
+            3.24    22.9   P         49.39    13.750     53.77    45.82   ...
             3.24    22.9   Pn        49.40    13.754     53.80    45.84   ...
         """
         kwargs = {}

obspy/clients/iris/tests/test_client.py

@@ -58,14 +58,18 @@ def test_distaz(self):
         client = Client()
         # normal request
         result = client.distaz(stalat=1.1, stalon=1.2, evtlat=3.2, evtlon=1.4)
-        self.assertAlmostEqual(result['distance'], 2.09554)
-        self.assertAlmostEqual(result['backazimuth'], 5.46946)
-        self.assertAlmostEqual(result['azimuth'], 185.47692)
+        self.assertAlmostEqual(result['distance'], 2.10256)
+        self.assertAlmostEqual(result['distancemeters'], 233272.79028)
+        self.assertAlmostEqual(result['backazimuth'], 5.46944)
+        self.assertAlmostEqual(result['azimuth'], 185.47695)
+        self.assertEqual(result['ellipsoidname'], 'WGS84')
         # w/o kwargs
         result = client.distaz(1.1, 1.2, 3.2, 1.4)
-        self.assertAlmostEqual(result['distance'], 2.09554)
-        self.assertAlmostEqual(result['backazimuth'], 5.46946)
-        self.assertAlmostEqual(result['azimuth'], 185.47692)
+        self.assertAlmostEqual(result['distance'], 2.10256)
+        self.assertAlmostEqual(result['distancemeters'], 233272.79028)
+        self.assertAlmostEqual(result['backazimuth'], 5.46944)
+        self.assertAlmostEqual(result['azimuth'], 185.47695)
+        self.assertEqual(result['ellipsoidname'], 'WGS84')
         # missing parameters
         self.assertRaises(Exception, client.distaz, stalat=1.1)
         self.assertRaises(Exception, client.distaz, 1.1)