def core_solve(self,
spf,
dpf,
phase_error=0.1,
amplitude_error=0.0,
leakage=0.0,
phase_only=True,
niter=200,
crosspol=False,
residual_tol=1e-6,
f=[100.0, 50.0, -10.0, 40.0]):
self.actualSetup(spf, dpf, f=f)
gt = create_gaintable_from_blockvisibility(self.vis)
log.info("Created gain table: %s" % (gaintable_summary(gt)))
gt = simulate_gaintable(gt,
phase_error=phase_error,
amplitude_error=amplitude_error,
leakage=leakage)
original = copy_visibility(self.vis)
vis = apply_gaintable(self.vis, gt)
gtsol = solve_gaintable(self.vis,
original,
phase_only=phase_only,
niter=niter,
crosspol=crosspol,
tol=1e-6)
vis = apply_gaintable(vis, gtsol, inverse=True)
residual = numpy.max(gtsol.residual)
assert residual < residual_tol, "%s %s Max residual = %s" % (spf, dpf,
residual)
log.debug(qa_gaintable(gt))
assert numpy.max(numpy.abs(gtsol.gain - 1.0)) > 0.1
def test_apply_gaintable_and_inverse_both(self):
for spf, dpf in [('stokesIQUV', 'linear'), ('stokesIQUV', 'circular')]:
self.actualSetup(spf, dpf)
gt = create_gaintable_from_blockvisibility(self.vis)
log.info("Created gain table: %s" % (gaintable_summary(gt)))
gt = simulate_gaintable(gt, phase_error=0.1, amplitude_error=0.1)
original = copy_visibility(self.vis)
vis = apply_gaintable(self.vis, gt)
vis = apply_gaintable(self.vis, gt, inverse=True)
error = numpy.max(numpy.abs(vis.vis - original.vis))
assert error < 1e-12, "Error = %s" % (error)
def ingest_visibility(self, freq=None, chan_width=None, times=None, reffrequency=None, add_errors=False,
block=True):
if freq is None:
freq = [1e8]
if times is None:
ntimes = 5
times = numpy.linspace(-numpy.pi / 3.0, numpy.pi / 3.0, ntimes)
if chan_width is None:
chan_width = [1e6]
if reffrequency is None:
reffrequency = [1e8]
lowcore = create_named_configuration('LOWBD2-CORE')
frequency = numpy.array([freq])
channel_bandwidth = numpy.array([chan_width])
phasecentre = SkyCoord(ra=+180.0 * u.deg, dec=-60.0 * u.deg, frame='icrs', equinox='J2000')
if block:
vt = create_blockvisibility(lowcore, times, frequency, channel_bandwidth=channel_bandwidth,
weight=1.0, phasecentre=phasecentre,
polarisation_frame=PolarisationFrame("stokesI"))
else:
vt = create_visibility(lowcore, times, frequency, channel_bandwidth=channel_bandwidth,
weight=1.0, phasecentre=phasecentre,
polarisation_frame=PolarisationFrame("stokesI"))
cellsize = 0.001
model = create_image_from_visibility(vt, npixel=self.npixel, cellsize=cellsize, npol=1,
frequency=reffrequency, phasecentre=phasecentre,
polarisation_frame=PolarisationFrame("stokesI"))
flux = numpy.array([[100.0]])
facets = 4
rpix = model.wcs.wcs.crpix - 1.0
spacing_pixels = self.npixel // facets
centers = [-1.5, -0.5, 0.5, 1.5]
comps = list()
for iy in centers:
for ix in centers:
p = int(round(rpix[0] + ix * spacing_pixels * numpy.sign(model.wcs.wcs.cdelt[0]))), \
int(round(rpix[1] + iy * spacing_pixels * numpy.sign(model.wcs.wcs.cdelt[1])))
sc = pixel_to_skycoord(p[0], p[1], model.wcs, origin=1)
comp = create_skycomponent(flux=flux, frequency=frequency, direction=sc,
polarisation_frame=PolarisationFrame("stokesI"))
comps.append(comp)
if block:
predict_skycomponent_blockvisibility(vt, comps)
else:
predict_skycomponent_visibility(vt, comps)
insert_skycomponent(model, comps)
self.model = copy_image(model)
self.empty_model = create_empty_image_like(model)
export_image_to_fits(model, '%s/test_pipeline_bags_model.fits' % self.dir)
if add_errors:
# These will be the same for all calls
numpy.random.seed(180555)
gt = create_gaintable_from_blockvisibility(vt)
gt = simulate_gaintable(gt, phase_error=1.0, amplitude_error=0.0)
vt = apply_gaintable(vt, gt)
return vt
def calibrate_blockvisibility(bvt: BlockVisibility,
model=None,
components=None,
predict=predict_2d,
**kwargs):
""" calibrate BlockVisibility with respect to model and optionally components
:param bvt: BlockVisibility
:param model: Model image
:param components: Sky components
:returns: Calibrated BlockVisibility
"""
assert model is not None or components is not None, "calibration requires a model or skycomponents"
if model is not None:
vtpred = convert_blockvisibility_to_visibility(bvt)
vtpred = predict(vtpred, model, **kwargs)
bvtpred = decoalesce_visibility(vtpred)
if components is not None:
bvtpred = predict_skycomponent_blockvisibility(bvtpred, components)
else:
bvtpred = copy_visibility(bvt, zero=True)
bvtpred = predict_skycomponent_blockvisibility(bvtpred, components)
gt = solve_gaintable(bvt, bvtpred, **kwargs)
return apply_gaintable(bvt, gt, **kwargs)
def insert_unittest_errors(vt, seed=180555):
"""Simulate gain errors and apply
:param vt:
:param phase_error:
:param amplitude_error:
:return:
"""
numpy.random.seed(seed)
controls = create_calibration_controls()
amp_errors = {'T': 0.0, 'G': 0.01, 'B': 0.01}
phase_errors = {'T': 1.0, 'G': 0.1, 'B': 0.01}
for c in "TGB":
gaintable = \
create_gaintable_from_blockvisibility(vt, timeslice=controls[c]['timeslice'])
gaintable = simulate_gaintable(
gaintable,
timeslice=controls[c]['timeslice'],
phase_only=controls[c]['phase_only'],
crosspol=controls[c]['shape'] == 'matrix',
phase_error=phase_errors[c],
amplitude_error=amp_errors[c])
vt = apply_gaintable(vt,
gaintable,
inverse=True,
timeslice=controls[c]['timeslice'])
return vt
def calibrate_visibility(vt: Visibility,
model: Image = None,
components=None,
predict=predict_2d,
**kwargs) -> Visibility:
""" calibrate Visibility with respect to model and optionally components
:param vt: Visibility
:param model: Model image
:param components: Sky components
:return: Calibrated visibility
"""
assert model is not None or components is not None, "calibration requires a model or skycomponents"
vtpred = copy_visibility(vt, zero=True)
if model is not None:
vtpred = predict(vtpred, model, **kwargs)
if components is not None:
vtpred = predict_skycomponent_visibility(vtpred, components)
else:
vtpred = predict_skycomponent_visibility(vtpred, components)
bvt = decoalesce_visibility(vt)
bvtpred = decoalesce_visibility(vtpred)
gt = solve_gaintable(bvt, bvtpred, **kwargs)
bvt = apply_gaintable(bvt,
gt,
inverse=get_parameter(kwargs, "inverse", False))
return convert_blockvisibility_to_visibility(bvt)
def peel_skycomponent_blockvisibility(vis: BlockVisibility, sc: Union[Skycomponent, List[Skycomponent]], remove=True)\
-> (BlockVisibility, List[GainTable]):
""" Peel a collection of components.
Sequentially solve the gain towards each Skycomponent and optionally remove the corrupted visibility from the
observed visibility.
:param params:
:param vis: Visibility to be processed
:param sc: Skycomponent or list of Skycomponents
:return: subtracted visibility and list of GainTables
"""
assert isinstance(
vis, BlockVisibility), "vis is not a BlockVisibility: %r" % vis
if not isinstance(sc, collections.Iterable):
sc = [sc]
gtlist = []
for comp in sc:
assert comp.shape == 'Point', "Cannot handle shape %s" % comp.shape
modelvis = copy_visibility(vis, zero=True)
modelvis = predict_skycomponent_blockvisibility(modelvis, comp)
gt = solve_gaintable(vis, modelvis, phase_only=False)
modelvis = apply_gaintable(modelvis, gt)
if remove:
vis.data['vis'] -= modelvis.data['vis']
gtlist.append(gt)
return vis, gtlist
def test_apply_gaintable_null(self):
for spf, dpf in[('stokesI', 'stokesI'), ('stokesIQUV', 'linear'), ('stokesIQUV', 'circular')]:
self.actualSetup(spf, dpf)
gt = create_gaintable_from_blockvisibility(self.vis, timeslice='auto')
gt.data['gain']*=0.0
original = copy_visibility(self.vis)
vis = apply_gaintable(self.vis, gt, inverse=True, timeslice='auto')
error = numpy.max(numpy.abs(vis.vis[:,0,1,...] - original.vis[:,0,1,...]))
assert error < 1e-12, "Error = %s" % (error)
def selfcal_single(vis, model, **kwargs):
if vis is not None:
predicted = copy_visibility(vis)
predicted = predict(predicted, model, **kwargs)
gtsol = solve_gaintable(vis, predicted, **kwargs)
vis = apply_gaintable(vis, gtsol, inverse=True, **kwargs)
return vis
else:
return None
def test_create_gaintable_from_visibility(self):
for spf, dpf in [('stokesIQUV', 'linear'), ('stokesIQUV', 'circular')]:
self.actualSetup(spf, dpf)
gt = create_gaintable_from_blockvisibility(self.vis)
log.info("Created gain table: %s" % (gaintable_summary(gt)))
gt = simulate_gaintable(gt, phase_error=0.1)
original = copy_visibility(self.vis)
vis = apply_gaintable(self.vis, gt)
assert numpy.max(numpy.abs(vis.vis - original.vis)) > 0.0
def create_blockvisibility_iterator(config: Configuration, times: numpy.array, frequency: numpy.array,
channel_bandwidth, phasecentre: SkyCoord, weight: float = 1,
polarisation_frame=PolarisationFrame('stokesI'), integration_time=1.0,
number_integrations=1, predict=predict_timeslice, model=None, components=None,
phase_error=0.0, amplitude_error=0.0, sleep=0.0, **kwargs) -> BlockVisibility:
""" Create a sequence of Visibilities and optionally predicting and coalescing
This is useful mainly for performing large simulations. Do something like::
vis_iter = create_blockvisibility_iterator(config, times, frequency, channel_bandwidth, phasecentre=phasecentre,
weight=1.0, integration_time=30.0, number_integrations=3)
for i, vis in enumerate(vis_iter):
if i == 0:
fullvis = vis
else:
fullvis = append_visibility(fullvis, vis)
:param config: Configuration of antennas
:param times: hour angles in radians
:param frequency: frequencies (Hz] Shape [nchan]
:param weight: weight of a single sample
:param phasecentre: phasecentre of observation
:param npol: Number of polarizations
:param integration_time: Integration time ('auto' or value in s)
:param number_integrations: Number of integrations to be created at each time.
:param model: Model image to be inserted
:param components: Components to be inserted
:param sleep_time: Time to sleep between yields
:return: Visibility
"""
for time in times:
actualtimes = time + numpy.arange(0, number_integrations) * integration_time * numpy.pi / 43200.0
bvis = create_blockvisibility(config, actualtimes, frequency=frequency, phasecentre=phasecentre, weight=weight,
polarisation_frame=polarisation_frame, integration_time=integration_time,
channel_bandwidth=channel_bandwidth)
if model is not None:
vis = predict(bvis, model, **kwargs)
bvis = convert_visibility_to_blockvisibility(vis)
if components is not None:
bvis = predict_skycomponent_blockvisibility(bvis, components)
# Add phase errors
if phase_error > 0.0 or amplitude_error > 0.0:
gt = create_gaintable_from_blockvisibility(bvis)
gt = simulate_gaintable(gt=gt, phase_error=phase_error, amplitude_error=amplitude_error)
vis = apply_gaintable(bvis, gt)
import time
time.sleep(sleep)
yield bvis
def test_apply_gaintable_only(self):
for spf, dpf in[('stokesI', 'stokesI'), ('stokesIQUV', 'linear'), ('stokesIQUV', 'circular')]:
self.actualSetup(spf, dpf)
gt = create_gaintable_from_blockvisibility(self.vis, timeslice='auto')
log.info("Created gain table: %s" % (gaintable_summary(gt)))
gt = simulate_gaintable(gt, phase_error=0.1, amplitude_error=0.01, timeslice='auto')
original = copy_visibility(self.vis)
vis = apply_gaintable(self.vis, gt, timeslice='auto')
error = numpy.max(numpy.abs(vis.vis - original.vis))
assert error > 10.0, "Error = %f" % (error)
def test_solve_gaintable_scalar(self):
self.actualSetup('stokesI', 'stokesI', f=[100.0])
gt = create_gaintable_from_blockvisibility(self.vis)
log.info("Created gain table: %s" % (gaintable_summary(gt)))
gt = simulate_gaintable(gt, phase_error=10.0, amplitude_error=0.0)
original = copy_visibility(self.vis)
self.vis = apply_gaintable(self.vis, gt)
gtsol = solve_gaintable(self.vis, original, phase_only=True, niter=200)
residual = numpy.max(gtsol.residual)
assert residual < 3e-8, "Max residual = %s" % (residual)
assert numpy.max(numpy.abs(gtsol.gain - 1.0)) > 0.1
def make_e(vis, calskymodel, evis_all):
# Return the estep for a given skymodel
evis = copy_visibility(vis)
tvis = copy_visibility(vis, zero=True)
tvis = predict_skycomponent_visibility(tvis, calskymodel[0].components)
tvis = apply_gaintable(tvis, calskymodel[1])
# E step is the data model for a window plus the difference between the observed data
# and the summed data models or, put another way, its the observed data minus the
# summed visibility for all other windows
evis.data['vis'][...] = tvis.data['vis'][...] + vis.data['vis'][
...] - evis_all.data['vis'][...]
return evis
def test_create_gaintable_from_visibility_interval(self):
for timeslice in [10.0, 'auto', 1e5]:
for spf, dpf in[('stokesIQUV', 'linear')]:
self.actualSetup(spf, dpf)
gt = create_gaintable_from_blockvisibility(self.vis, timeslice=timeslice)
log.info("Created gain table: %s" % (gaintable_summary(gt)))
gt = simulate_gaintable(gt, phase_error=1.0, timeslice=timeslice)
original = copy_visibility(self.vis)
vis = apply_gaintable(self.vis, gt, timeslice=timeslice)
assert numpy.max(numpy.abs(original.vis)) > 0.0
assert numpy.max(numpy.abs(vis.vis)) > 0.0
assert numpy.max(numpy.abs(vis.vis - original.vis)) > 0.0
def calibrate_function(vis, model_vis, context='T', controls=None, iteration=0, **kwargs):
""" Calibrate using algorithm specified by context
The context string can denote a sequence of calibrations e.g. TGB with different timescales.
:param vis:
:param model_vis:
:param context: calibration contexts in order of correction e.g. 'TGB'
:param control: controls dictionary, modified as necessary
:param iteration: Iteration number to be compared to the 'first_selfcal' field.
:param kwargs:
:return: Calibrated data, dict(gaintables)
"""
gaintables = {}
if controls is None:
controls = create_calibration_controls(**kwargs)
isVis = isinstance(vis, Visibility)
if isVis:
avis = convert_visibility_to_blockvisibility(vis)
else:
avis = vis
isMVis = isinstance(model_vis, Visibility)
if isMVis:
amvis = convert_visibility_to_blockvisibility(model_vis)
else:
amvis = model_vis
for c in context:
if iteration >= controls[c]['first_selfcal']:
gaintables[c] = \
create_gaintable_from_blockvisibility(avis,
timeslice=controls[c]['timeslice'])
gaintables[c] = solve_gaintable(avis, amvis,
timeslice=controls[c]['timeslice'],
phase_only=controls[c]['phase_only'],
crosspol=controls[c]['shape'] == 'matrix')
log.debug('calibrate_function: Jones matrix %s, iteration %d' % (c, iteration))
log.debug(qa_gaintable(gaintables[c], context='Jones matrix %s, iteration %d' % (c, iteration)))
avis = apply_gaintable(avis, gaintables[c],
inverse=True,
timeslice=controls[c]['timeslice'])
else:
log.debug('calibrate_function: Jones matrix %s not solved, iteration %d' % (c, iteration))
if isVis:
return convert_blockvisibility_to_visibility(avis), gaintables
else:
return avis, gaintables
def skymodel_cal_e_step(vis: BlockVisibility, evis_all: BlockVisibility, calskymodel, **kwargs):
"""Calculates E step in equation A12
This is the data model for this window plus the difference between observed data and summed data models
:param evis_all: Sum data models
:param csm: csm element being fit
:param kwargs:
:return: Data model (i.e. visibility) for this csm
"""
evis = copy_visibility(evis_all)
tvis = copy_visibility(vis, zero=True)
tvis = predict_skycomponent_visibility(tvis, calskymodel[0].components)
tvis = apply_gaintable(tvis, calskymodel[1])
evis.data['vis'][...] = tvis.data['vis'][...] + vis.data['vis'][...] - evis_all.data['vis'][...]
return evis
def sagecal_e_all(vis: BlockVisibility, thetas, **kwargs):
"""Calculates E step in equation A12
This is the sum of the data models over all windows
:param vis:
:param thetas:
:param kwargs:
:return:
"""
evis = copy_visibility(vis, zero=True)
tvis = copy_visibility(vis, zero=True)
for i, theta in enumerate(thetas):
tvis.data['vis'][...] = 0.0
tvis = predict_skycomponent_visibility(tvis, theta[0])
tvis = apply_gaintable(tvis, theta[1])
evis.data['vis'][...] += tvis.data['vis'][...]
return evis
def skymodel_cal_e_all(vis: BlockVisibility, calskymodels):
"""Calculates E step in equation A12
This is the sum of the data models over all skymodel
:param vis: Visibility
:param csm: List of (skymodel, gaintable) tuples
:param kwargs:
:return: Sum of data models (i.e. a visibility)
"""
evis = copy_visibility(vis, zero=True)
tvis = copy_visibility(vis, zero=True)
for csm in calskymodels:
tvis.data['vis'][...] = 0.0
tvis = predict_skycomponent_visibility(tvis, csm[0].components)
tvis = apply_gaintable(tvis, csm[1])
evis.data['vis'][...] += tvis.data['vis'][...]
return evis
def ingest_visibility(self, freq=1e8, chan_width=1e6, times=None, reffrequency=None, add_errors=False):
if times is None:
times = [0.0]
if reffrequency is None:
reffrequency = [1e8]
lowcore = create_named_configuration('LOWBD2-CORE')
frequency = numpy.array([freq])
channel_bandwidth = numpy.array([chan_width])
# phasecentre = SkyCoord(ra=+180.0 * u.deg, dec=-60.0 * u.deg, frame='icrs', equinox='J2000')
# Observe at zenith to ensure that timeslicing works well. We test that elsewhere.
phasecentre = SkyCoord(ra=+180.0 * u.deg, dec=-60.0 * u.deg, frame='icrs', equinox='J2000')
vt = create_blockvisibility(lowcore, times, frequency, channel_bandwidth=channel_bandwidth,
weight=1.0, phasecentre=phasecentre,
polarisation_frame=PolarisationFrame("stokesI"))
cellsize = 0.001
model = create_image_from_visibility(vt, npixel=self.npixel, cellsize=cellsize, npol=1,
frequency=reffrequency,
polarisation_frame=PolarisationFrame("stokesI"))
flux = numpy.array([[100.0]])
facets = 4
rpix = model.wcs.wcs.crpix - 1.0
spacing_pixels = self.npixel // facets
centers = [-1.5, -0.5, 0.5, 1.5]
comps = list()
for iy in centers:
for ix in centers:
p = int(round(rpix[0] + ix * spacing_pixels * numpy.sign(model.wcs.wcs.cdelt[0]))), \
int(round(rpix[1] + iy * spacing_pixels * numpy.sign(model.wcs.wcs.cdelt[1])))
sc = pixel_to_skycoord(p[0], p[1], model.wcs, origin=1)
comps.append(create_skycomponent(flux=flux, frequency=vt.frequency, direction=sc,
polarisation_frame=PolarisationFrame("stokesI")))
predict_skycomponent_blockvisibility(vt, comps)
insert_skycomponent(model, comps)
self.actualmodel = copy_image(model)
export_image_to_fits(model, '%s/test_imaging_model.fits' % (self.results_dir))
if add_errors:
# These will be the same for all calls
numpy.random.seed(180555)
gt = create_gaintable_from_blockvisibility(vt)
gt = simulate_gaintable(gt, phase_error=1.0, amplitude_error=0.0)
vt = apply_gaintable(vt, gt)
return vt
def sagecal_e_step(vis: BlockVisibility,
evis_all: BlockVisibility,
theta,
beta=1.0,
**kwargs):
"""Calculates E step in equation A12
This is the data model for this window plus the difference between observed data and summed data models
:param vis:
:param theta:
:param kwargs:
:return:
"""
evis = copy_visibility(evis_all)
tvis = copy_visibility(vis, zero=True)
tvis = predict_skycomponent_visibility(tvis, theta[0])
tvis = apply_gaintable(tvis, theta[1])
evis.data['vis'][...] = tvis.data['vis'][...] + \
beta * (vis.data['vis'][...] - evis_all.data['vis'][...])
return evis
def actualSetup(self, sky_pol_frame='stokesI', data_pol_frame='stokesI', f=None, vnchan=1, doiso=True,
ntimes=1, flux_limit=18.0):
nfreqwin = vnchan
ntimes = ntimes
rmax = 300.0
npixel = 1024
cellsize = 0.001
frequency = numpy.linspace(0.8e8, 1.2e8, nfreqwin)
if nfreqwin > 1:
channel_bandwidth = numpy.array(nfreqwin * [frequency[1] - frequency[0]])
else:
channel_bandwidth = [0.4e8]
times = numpy.linspace(-numpy.pi / 3.0, numpy.pi / 3.0, ntimes)
phasecentre = SkyCoord(ra=+0.0 * u.deg, dec=-45.0 * u.deg, frame='icrs', equinox='J2000')
lowcore = create_named_configuration('LOWBD2', rmax=rmax)
block_vis = create_blockvisibility(lowcore, times, frequency=frequency, channel_bandwidth=channel_bandwidth,
weight=1.0, phasecentre=phasecentre,
polarisation_frame=PolarisationFrame("stokesI"))
block_vis.data['uvw'][..., 2] = 0.0
self.beam = create_image_from_visibility(block_vis, npixel=npixel, frequency=[numpy.average(frequency)],
nchan=nfreqwin,
channel_bandwidth=[numpy.sum(channel_bandwidth)], cellsize=cellsize,
phasecentre=phasecentre)
self.components = create_low_test_skycomponents_from_gleam(flux_limit=flux_limit, phasecentre=phasecentre,
frequency=frequency,
polarisation_frame=PolarisationFrame('stokesI'),
radius=npixel * cellsize)
self.beam = create_low_test_beam(self.beam)
self.components = apply_beam_to_skycomponent(self.components, self.beam, flux_limit=flux_limit / 100.0)
print("Number of components %d" % len(self.components))
self.vis = copy_visibility(block_vis, zero=True)
gt = create_gaintable_from_blockvisibility(block_vis, timeslice='auto')
for i, sc in enumerate(self.components):
if sc.flux[0, 0] > 10:
sc.flux[...] /= 10.0
print('Component %d, flux = %s' % (i, str(sc.flux[0, 0])))
component_vis = copy_visibility(block_vis, zero=True)
gt = simulate_gaintable(gt, amplitude_error=0.0, phase_error=0.1, seed=None)
component_vis = predict_skycomponent_visibility(component_vis, sc)
component_vis = apply_gaintable(component_vis, gt)
self.vis.data['vis'][...] += component_vis.data['vis'][...]
# Do an isoplanatic selfcal
self.model_vis = copy_visibility(self.vis, zero=True)
self.model_vis = predict_skycomponent_visibility(self.model_vis, self.components)
if doiso:
gt = solve_gaintable(self.vis, self.model_vis, phase_only=True, timeslice='auto')
self.vis = apply_gaintable(self.vis, gt, inverse=True)
self.model_vis = convert_blockvisibility_to_visibility(self.model_vis)
self.model_vis, _, _ = weight_visibility(self.model_vis, self.beam)
self.dirty_model, sumwt = invert_function(self.model_vis, self.beam, context='2d')
export_image_to_fits(self.dirty_model, "%s/test_sagecal-model_dirty.fits" % self.dir)
lvis = convert_blockvisibility_to_visibility(self.vis)
lvis, _, _ = weight_visibility(lvis, self.beam)
dirty, sumwt = invert_function(lvis, self.beam, context='2d')
print(qa_image(dirty))
export_image_to_fits(dirty, "%s/test_sagecal-initial_dirty.fits" % self.dir)
block_vis=convert_visibility_to_blockvisibility(predicted_vis)
#print("np.sum(block_vis.data): ", numpy.sum(block_vis.data['vis']))
#print("nchan npol nants ", block_vis.nchan, block_vis.npol, block_vis.nants)
#print("uvw", block_vis.uvw, numpy.sum(block_vis.uvw))
#print("vis", block_vis.vis, numpy.sum(block_vis.vis))
#print("weight", block_vis.weight, numpy.sum(block_vis.weight))
#print("time", block_vis.time, numpy.sum(block_vis.time))
#print("integration_time", block_vis.integration_time, numpy.sum(block_vis.integration_time))
#print("nvis, size", block_vis.nvis, block_vis.size())
gt = create_gaintable_from_blockvisibility(block_vis)
#print("np.sum(gt.data): ", numpy.sum(gt.data['gain']))
gt = simulate_gaintable(gt, phase_error=1.0)
#print("np.sum(gt.data): ", numpy.sum(gt.data['gain']))
blockvis = apply_gaintable(block_vis, gt)
#print("np.sum(blockvis.data): ", numpy.sum(blockvis.data['vis']))
model = create_image_from_visibility(block_vis, npixel=npixel, frequency=[numpy.average(frequency)], nchan=1,
channel_bandwidth=[numpy.sum(channel_bandwidth)], cellsize=cellsize, phasecentre=phasecentre)
#print("model sum, min, max, shape: ", numpy.sum(model.data), numpy.amin(model.data), numpy.amax(model.data), model.shape)
print(qa_image(model, context='Blockvis model image'))
export_image_to_fits(model, '%s/imaging-blockvis_model.fits'
% (results_dir))
dirty, sumwt = invert_function(predicted_vis, model, vis_slices=vis_slices, dopsf=False, context='wstack')
def corrupt_vis(vis, gt, **kwargs):
if gt is None:
gt = create_gaintable_from_blockvisibility(vis, **kwargs)
gt = simulate_gaintable(gt, **kwargs)
return apply_gaintable(vis, gt)
def predict_and_apply(ovis, calskymodel):
tvis = copy_visibility(ovis, zero=True)
tvis = predict_skycomponent_visibility(tvis, calskymodel[0].components)
tvis = apply_gaintable(tvis, calskymodel[1])
return tvis
def solve_and_apply(vis, modelvis):
gt = solve_gaintable(vis, modelvis, **kwargs)
return apply_gaintable(vis, gt, **kwargs)
def test_peel_skycomponent_blockvisibility(self):
df = 1e6
frequency = numpy.array([1e8 - df, 1e8, 1e8 + df])
channel_bandwidth = numpy.array([df, df, df])
# Define the component and give it some spectral behaviour
f = numpy.array([100.0, 20.0, -10.0, 1.0])
flux = numpy.array([f, 0.8 * f, 0.6 * f])
phasecentre = SkyCoord(0 * u.deg, -60.0 * u.deg)
config = create_named_configuration('LOWBD2-CORE')
peeldirection = SkyCoord(+15 * u.deg, -60.0 * u.deg)
times = numpy.linspace(-3.0, 3.0, 7) * numpy.pi / 12.0
# Make the visibility
vis = create_blockvisibility(
config,
times,
frequency,
phasecentre=phasecentre,
weight=1.0,
polarisation_frame=PolarisationFrame('linear'),
channel_bandwidth=channel_bandwidth)
vis.data['vis'][...] = 0.0
# First add in the source to be peeled.
peel = Skycomponent(direction=peeldirection,
frequency=frequency,
flux=flux,
polarisation_frame=PolarisationFrame("stokesIQUV"))
vis = predict_skycomponent_visibility(vis, peel)
# Make a gaintable and apply it to the visibility of the peeling source
gt = create_gaintable_from_blockvisibility(vis, timeslice='auto')
gt = simulate_gaintable(gt,
phase_error=0.01,
amplitude_error=0.01,
timeslice='auto')
gt.data['gain'] *= 0.3
vis = apply_gaintable(vis, gt, timeslice='auto')
# Now create a plausible field using the GLEAM sources
model = create_image_from_visibility(
vis,
cellsize=0.001,
frequency=frequency,
polarisation_frame=PolarisationFrame('stokesIQUV'))
bm = create_low_test_beam(model=model)
sc = create_low_test_skycomponents_from_gleam(
flux_limit=1.0,
polarisation_frame=PolarisationFrame("stokesIQUV"),
frequency=frequency,
kind='cubic',
phasecentre=phasecentre,
radius=0.1)
sc = apply_beam_to_skycomponent(sc, bm)
# Add in the visibility due to these sources
vis = predict_skycomponent_visibility(vis, sc)
assert numpy.max(numpy.abs(vis.vis)) > 0.0
# Now we can peel
vis, peel_gts = peel_skycomponent_blockvisibility(vis, peel)
assert len(peel_gts) == 1
residual = numpy.max(peel_gts[0].residual)
assert residual < 0.7, "Peak residual %.6f too large" % (residual)
im, sumwt = invert_timeslice(vis, model, timeslice='auto')
qa = qa_image(im)
assert numpy.abs(qa.data['max'] - 14.2) < 1.0, str(qa)