class StreamSetup:
def setup(self):
self.fh = baseband.open(baseband.data.SAMPLE_VDIF)
self.data = self.fh.read()
self.fh.seek(0)
frequency = 311.25 * u.MHz + (np.arange(8.) // 2) * 16. * u.MHz
sideband = np.tile([-1, +1], 4)
self.wrapped = SetAttribute(self.fh,
frequency=frequency,
sideband=sideband)
def teardown(self):
self.wrapped.close()
self.fh.close()
def check(self, stream, header, attrs=None, exclude=()):
if attrs is None:
if hasattr(stream, 'bps'):
attrs = ('sample_shape', 'sample_rate', 'time', 'bps',
'complex_data')
exclude = ('dtype', )
else:
attrs = ('sample_shape', 'dtype', 'sample_rate', 'time',
'frequency', 'sideband')
is_header = isinstance(header, hdf5.HDF5Header)
if 'shape' not in exclude:
assert stream.shape[0] == header.samples_per_frame
if is_header:
assert stream.shape[0] == header['samples_per_frame']
for attr in attrs:
stream_attr = getattr(stream,
(attr if attr != 'time' else 'start_time'))
header_attr = getattr(header, attr)
if attr == 'time':
assert np.all(np.abs(header_attr - stream_attr) < 1. * u.ns)
else:
assert np.all(header_attr == stream_attr)
if is_header:
if attr in exclude:
assert attr not in header
else:
header_value = header[attr]
assert np.all(header_value == stream_attr)
def test_set_start_time(self):
expected = self.fh.read()
offset = 0.1 * u.s
sa = SetAttribute(self.fh, start_time=self.fh.start_time + offset)
assert sa.start_time == self.fh.start_time + offset
for attr in ('sample_rate', 'samples_per_frame', 'shape', 'dtype'):
assert getattr(sa, attr) == getattr(self.fh, attr)
data = sa.read()
assert np.all(data == expected)
sa.seek(10)
data2 = sa.read(10)
assert np.all(data2 == expected[10:20])
sa.seek(10 / sa.sample_rate)
data3 = sa.read(10)
assert np.all(data3 == expected[10:20])
sa.seek(sa.start_time + 10 / self.fh.sample_rate)
data4 = sa.read(10)
assert np.all(data4 == expected[10:20])
for attr in ('frequency', 'sideband', 'polarization'):
with pytest.raises(AttributeError):
getattr(sa, attr)
sa.close()
def test_set_basics(self):
expected = self.fh.read()
frequency = 311.25 * u.MHz + (np.arange(8.) // 2) * 16. * u.MHz
sideband = np.tile([-1, +1], 4)
sa = SetAttribute(self.fh, frequency=frequency, sideband=sideband)
assert np.all(sa.frequency == frequency)
assert np.all(sa.sideband == sideband)
for attr in ('start_time', 'sample_rate', 'samples_per_frame', 'shape',
'dtype'):
assert getattr(sa, attr) == getattr(self.fh, attr)
# Check that frequency does not propagate.
frequency[...] = 0
assert np.all(sa.frequency != 0)
sideband[...] = 0
assert np.all(np.abs(sa.sideband) == 1)
# Check data can be read.
data = sa.read()
assert np.all(data == expected)
# Check we didn't magically define polarization.
with pytest.raises(AttributeError):
sa.polarization
sa.close()