Added tests for converting to/from XYZ from HEDZ.

geomagio/StreamConverter_test.py

+
+import obspy.core
+import numpy
+import StreamConverter
+
+assert_equals = numpy.testing.assert_equal
+assert_almost_equals = numpy.testing.assert_almost_equal
+
+cos = numpy.cos
+sin = numpy.sin
+# tan = math.tan
+
+D2R = numpy.pi / 180
+M2I = 60 * 10               # Minutes to Iaga Decbas
+STARTTIME = obspy.core.UTCDateTime('2014-11-01')
+
+stats = obspy.core.Stats()
+stats.comments = ""
+stats.starttime = STARTTIME
+stats.sampling_rate = 0.0166666666667
+stats.npts = 1
+stats.DECBAS = 0
+
+"""Unit Tests for StreamConverter
+
+Notes
+-----
+
+We are using triangle identities for variables to test with.  Specifically
+    the hypotenuse is normally equal to 1, causing the adjacent angle length
+    to be cos(angle) and the opposite length to be sin(angle)
+
+For more info on the components see the Notes in ChannelConverterTest.py.
+"""
+
+
+def test_get_geo_from_obs():
+    """geomag.StreamConverter.test_get_geo_from_obs()
+
+    The observatory stream containing the observatory traces
+    ''h'', ''d'' or ''e'', ''z'', and ''f'' converts to the geographic
+    stream containing the traces ''x'', ''y'', ''z'', and ''f''
+    """
+    obs = obspy.core.Stream()
+
+    # 1) call get_geo_from_obs using equal h, e streams with a decbas of 0
+    #   the geographic stream values X, Y will be the same.
+    stats.DECBAS = 0
+    stats.npts = 1
+    obs += __create_trace('H', [1])
+    obs += __create_trace('E', [1])
+    obs += __create_trace('Z', [1])
+    obs += __create_trace('F', [1])
+    geo = StreamConverter.get_geo_from_obs(obs)
+    X = geo.select(channel='X')[0].data
+    Y = geo.select(channel='Y')[0].data
+    assert_almost_equals(X[0], 1, 8, 'Expect X to almost equal 1', True)
+    assert_almost_equals(Y[0], 1, 8, 'Expect Y to almost equal 1', True)
+
+    # 2) call get_geo_from_obs using a decbas of 15 degrees, and streams
+    #   with H = [cos(15), cos(30)], and E = [sin(15), sin(30)].
+    #   Expect treams of X = [cos(30), cos(45)] and Y = sin(30), sin(45)
+    obs = obspy.core.Stream()
+    stats.DECBAS = 15 * M2I
+    stats.npts = 2
+    obs += __create_trace('H', [cos(15 * D2R), cos(30 * D2R)])
+    obs += __create_trace('E', [sin(15 * D2R), sin(30 * D2R)])
+    obs += __create_trace('Z', [1, 1])
+    obs += __create_trace('F', [1, 1])
+    geo = StreamConverter.get_geo_from_obs(obs)
+    X = geo.select(channel='X')[0].data
+    Y = geo.select(channel='Y')[0].data
+    assert_equals(X, [cos(30 * D2R), cos(45 * D2R)],
+        'Expect X to equal [cos(30), cos(45)]', True)
+    assert_equals(Y, [sin(30 * D2R), sin(45 * D2R)],
+        'Expect Y to equal [sin(30), sin(45)]', True)
+
+
+def test_get_obs_from_geo():
+    """geomag.StreamConverter.test_get_obs_from_geo()
+
+    The geographic stream containing the traces ''x'', ''y'', ''z'', and
+    ''f'' converts to the observatory stream containing the traces
+    ''h'', ''d'' or ''e'', ''z'', and ''f''.
+    """
+    geo = obspy.core.Stream()
+
+    # call get_geo_from_obs using a decbas of 15, a X stream of
+    #   [cos(30), cos(45)], and a Y stream of [sin(30), sin(45)].
+    #   Expect a H stream of [cos(15), cos(30)] and a
+    #   E stream of [sin(15), sin(30)]
+    stats.DECBAS = 15 * M2I
+    stats.npts = 2
+    geo += __create_trace('X', [cos(30 * D2R), cos(45 * D2R)])
+    geo += __create_trace('Y', [sin(30 * D2R), sin(45 * D2R)])
+    geo += __create_trace('Z', [1, 1])
+    geo += __create_trace('F', [1, 1])
+    obs = StreamConverter.get_obs_from_geo(geo, True)
+    H = obs.select(channel='H')[0].data
+    E = obs.select(channel='E')[0].data
+    D = obs.select(channel='D')[0].data
+    assert_almost_equals(H, [cos(15 * D2R), cos(30 * D2R)], 8,
+        'Expect H to equal [cos(15), cos(30)]', True)
+    assert_almost_equals(E, [sin(15 * D2R), sin(30 * D2R)], 8,
+        'Expect E to equal [sin(15), sin(30)', True)
+    assert_almost_equals(D, [15 * D2R, 30 * D2R], 8,
+        'Expect D to equal [15 degress, 30 degrees]', True)
+
+
+def test_get_obs_from_obs():
+    """geomag.StreamConverter.test_get_obs_from_obs()
+
+    The observatory stream can contain either ''d'' or ''e'' depending
+    on it's source. get_obs_from_obs will return either or both as part
+    of the obs Stream.
+    """
+
+    # 1) Call get_obs_from_obs using a decbas of 15, a H stream of
+    #   [cos(15), cos(30)], a E stream of [sin(15), sin(30)].
+    #   Expect a D stream of [15 degrees, 30 degrees]
+    obs_e = obspy.core.Stream()
+    stats.DECBAS = 15 * M2I
+    stats.npts = 2
+    obs_e += __create_trace('H', [cos(15 * D2R), cos(30 * D2R)])
+    obs_e += __create_trace('E', [sin(15 * D2R), sin(30 * D2R)])
+    obs_e += __create_trace('Z', [1, 1])
+    obs_e += __create_trace('F', [1, 1])
+    obs_D = StreamConverter.get_obs_from_obs(obs_e, False, True)
+    d = obs_D.select(channel='D')[0].data
+    assert_almost_equals(d, [15 * D2R, 30 * D2R], 8)
+
+    # 2) Call get_obs_from_obs using a decbase of 15 degrees, a H stream of
+    #   [cos(15), cos(30)], and a D stream of [15, 30].
+    #   Expect a D stream of [sin(15), sin(30)]
+    obs_d = obspy.core.Stream()
+    obs_d += __create_trace('H', [cos(15 * D2R), cos(30 * D2R)])
+    obs_d += __create_trace('D', [15 * D2R, 30 * D2R])
+    obs_d += __create_trace('Z', [1, 1])
+    obs_d += __create_trace('F', [1, 1])
+    obs_E = StreamConverter.get_obs_from_obs(obs_d, True, False)
+    e = obs_E.select(channel='E')[0].data
+    assert_almost_equals(e, [sin(15 * D2R), sin(30 * D2R)], 8,
+        'Expect E to equal [sin(15), sin(30)')
+
+
+def __create_trace(channel, data):
+    """
+    Utility to create a trace containing the given numpy array.
+
+    Parameters
+    ----------
+    channel: string
+        The name of the trace being created.
+    data: array
+        The array to be inserted into the trace.
+
+    Returns
+    -------
+    obspy.core.Stream
+        Stream containing the channel.
+    """
+    stats.channel = channel
+    numpy_data = numpy.array(data, dtype=numpy.float64)
+    return obspy.core.Trace(numpy_data, stats)