def copy_skymodel(sm):
""" Copy a sky model
"""
if sm.components is not None:
newcomps = [copy_skycomponent(comp) for comp in sm.components]
else:
newcomps = None
if sm.image is not None:
newimage = copy_image(sm.image)
else:
newimage = None
if sm.mask is not None:
newmask = copy_image(sm.mask)
else:
newmask = None
if sm.gaintable is not None:
newgt = copy_gaintable(sm.gaintable)
else:
newgt = None
return SkyModel(components=newcomps, image=newimage, gaintable=newgt, mask=newmask,
fixed=sm.fixed)
def solve_skymodel(vis, skymodel, gain=0.1, **kwargs):
"""Fit a single skymodel to a visibility
:param evis: Expected vis for this ssm
:param modelpartition: scm element being fit i.e. (skymodel, gaintable) tuple
:param gain: Gain in step
:param method: 'fit' or 'sum'
:param kwargs:
:return: skycomponent
"""
if skymodel.fixed:
return skymodel
new_comps = list()
for comp in skymodel.components:
new_comp = copy_skycomponent(comp)
new_comp, _ = fit_visibility(vis, new_comp)
new_comp.flux = gain * new_comp.flux + (1.0 - gain) * comp.flux
new_comps.append(new_comp)
new_images = list()
for im in skymodel.images:
new_image = copy_image(im)
# new_image = solve_image_arlexecute_workflow(vis, new_image, **kwargs)
new_images.append(new_image)
return SkyModel(components=new_comps, images=new_images)
def show_components(im, comps, npixels=128, fig=None, vmax=None, vmin=None):
""" Show components against an image
:param im:
:param comps:
:param npixels:
:param fig:
:return:
"""
import matplotlib.pyplot as plt
if vmax is None:
vmax = numpy.max(im.data[0, 0, ...])
if vmin is None:
vmin = numpy.min(im.data[0, 0, ...])
if not fig:
fig = plt.figure()
plt.clf()
for isc, sc in enumerate(comps):
newim = copy_image(im)
plt.subplot(111, projection=newim.wcs.sub([1, 2]))
centre = numpy.round(skycoord_to_pixel(sc.direction, newim.wcs, 1, 'wcs')).astype('int')
newim.data = newim.data[:, :,
(centre[1] - npixels // 2):(centre[1] + npixels // 2),
(centre[0] - npixels // 2):(centre[0] + npixels // 2)]
newim.wcs.wcs.crpix[0] -= centre[0] - npixels // 2
newim.wcs.wcs.crpix[1] -= centre[1] - npixels // 2
plt.imshow(newim.data[0, 0, ...], origin='lower', cmap='Greys', vmax=vmax, vmin=vmin)
x, y = skycoord_to_pixel(sc.direction, newim.wcs, 0, 'wcs')
plt.plot(x, y, marker='+', color='red')
plt.title('Name = %s, flux = %s' % (sc.name, sc.flux))
plt.show()
def ft_cal_sm(ov, sm):
assert isinstance(ov, Visibility), ov
assert isinstance(sm, SkyModel), sm
v = copy_visibility(ov)
v.data['vis'][...] = 0.0 + 0.0j
if len(sm.components) > 0:
if isinstance(sm.mask, Image):
comps = copy_skycomponent(sm.components)
comps = apply_beam_to_skycomponent(comps, sm.mask)
v = predict_skycomponent_visibility(v, comps)
else:
v = predict_skycomponent_visibility(v, sm.components)
if isinstance(sm.image, Image):
if numpy.max(numpy.abs(sm.image.data)) > 0.0:
if isinstance(sm.mask, Image):
model = copy_image(sm.image)
model.data *= sm.mask.data
else:
model = sm.image
v = predict_list_serial_workflow([v], [model],
context=context,
vis_slices=vis_slices,
facets=facets,
gcfcf=gcfcf,
**kwargs)[0]
if docal and isinstance(sm.gaintable, GainTable):
bv = convert_visibility_to_blockvisibility(v)
bv = apply_gaintable(bv, sm.gaintable, inverse=True)
v = convert_blockvisibility_to_visibility(bv)
return v
def deconvolve(dirty, psf, model, facet, gthreshold, msk=None):
if prefix == '':
lprefix = "facet %d" % facet
else:
lprefix = "%s, facet %d" % (prefix, facet)
if nmoment > 0:
moment0 = calculate_image_frequency_moments(dirty)
this_peak = numpy.max(numpy.abs(
moment0.data[0, ...])) / dirty.data.shape[0]
else:
ref_chan = dirty.data.shape[0] // 2
this_peak = numpy.max(numpy.abs(dirty.data[ref_chan, ...]))
if this_peak > 1.1 * gthreshold:
kwargs['threshold'] = gthreshold
result, _ = deconvolve_cube(dirty,
psf,
prefix=lprefix,
mask=msk,
**kwargs)
if result.data.shape[0] == model.data.shape[0]:
result.data += model.data
return result
else:
return copy_image(model)
def restore_cube(model: Image, psf: Image, residual=None, **kwargs) -> Image:
""" Restore the model image to the residuals
:params psf: Input PSF
:return: restored image
"""
assert isinstance(model, Image), model
assert isinstance(psf, Image), psf
assert residual is None or isinstance(residual, Image), residual
restored = copy_image(model)
npixel = psf.data.shape[3]
sl = slice(npixel // 2 - 7, npixel // 2 + 8)
size = get_parameter(kwargs, "psfwidth", None)
if size is None:
# isotropic at the moment!
from scipy.optimize import minpack
try:
fit = fit_2dgaussian(psf.data[0, 0, sl, sl])
if fit.x_stddev <= 0.0 or fit.y_stddev <= 0.0:
log.debug(
'restore_cube: error in fitting to psf, using 1 pixel stddev'
)
size = 1.0
else:
size = max(fit.x_stddev, fit.y_stddev)
log.debug('restore_cube: psfwidth = %s' % (size))
except minpack.error as err:
log.debug('restore_cube: minpack error, using 1 pixel stddev')
size = 1.0
except ValueError as err:
log.debug(
'restore_cube: warning in fit to psf, using 1 pixel stddev')
size = 1.0
else:
log.debug('restore_cube: Using specified psfwidth = %s' % (size))
# TODO: Remove filter when astropy fixes convolve
import warnings
warnings.simplefilter(action='ignore', category=FutureWarning)
from astropy.convolution import Gaussian2DKernel, convolve_fft
# By convention, we normalise the peak not the integral so this is the volume of the Gaussian
norm = 2.0 * numpy.pi * size**2
gk = Gaussian2DKernel(size)
for chan in range(model.shape[0]):
for pol in range(model.shape[1]):
restored.data[chan, pol, :, :] = norm * convolve_fft(
model.data[chan, pol, :, :],
gk,
normalize_kernel=False,
allow_huge=True)
if residual is not None:
restored.data += residual.data
return restored
def copy_skymodel(sm):
""" Copy a sky model
"""
return SkyModel(
components=[copy_skycomponent(comp) for comp in sm.components],
images=[copy_image(im) for im in sm.images],
fixed=sm.fixed)
def partition_skymodel_by_flux(sc, model, flux_threshold=-numpy.inf):
"""Partition skymodel according to flux
:param sc:
:param model:
:param flux_threshold:
:return:
"""
brightsc = filter_skycomponents_by_flux(sc, flux_min=flux_threshold)
weaksc = filter_skycomponents_by_flux(sc, flux_max=flux_threshold)
log.info('Converted %d components into %d bright components and one image containing %d components'
% (len(sc), len(brightsc), len(weaksc)))
im = copy_image(model)
im = insert_skycomponent(im, weaksc)
return SkyModel(components=[copy_skycomponent(comp) for comp in brightsc],
image=copy_image(im), mask=None,
fixed=False)
def expand_skymodel_by_skycomponents(sm, **kwargs):
""" Expand a sky model so that all components and the image are in separate skymodels
The mask and gaintable are taken to apply for all new skymodels.
:param sm: SkyModel
:return: List of SkyModels
"""
result = [SkyModel(components=[comp],
image=None,
gaintable=copy_gaintable(sm.gaintable),
mask=copy_image(sm.mask),
fixed=sm.fixed) for comp in sm.components]
if sm.image is not None:
result.append(SkyModel(components=None,
image=copy_image(sm.image),
gaintable=copy_gaintable(sm.gaintable),
mask=copy_image(sm.mask),
fixed=sm.fixed))
return result
def calculate_image_from_frequency_moments(im: Image,
moment_image: Image,
reference_frequency=None) -> Image:
"""Calculate image from frequency weighted moments
Weights are ((freq-reference_frequency)/reference_frequency)**moment
Note that a new image is created
For example, to find the moments and then reconstruct from just the moments::
moment_cube = calculate_image_frequency_moments(model_multichannel, nmoments=5)
reconstructed_cube = calculate_image_from_frequency_moments(model_multichannel, moment_cube)
:param im: Image cube to be reconstructed
:param moment_image: Moment cube (constructed using calculate_image_frequency_moments)
:param reference_frequency: Reference frequency (default None uses average)
:return: reconstructed image
"""
assert isinstance(im, Image)
nchan, npol, ny, nx = im.shape
nmoments, mnpol, mny, mnx = moment_image.shape
assert npol == mnpol
assert ny == mny
assert nx == mnx
assert moment_image.wcs.wcs.ctype[
3] == 'MOMENT', "Second image should be a moment image"
channels = numpy.arange(nchan)
with warnings.catch_warnings():
warnings.simplefilter('ignore', FITSFixedWarning)
freq = im.wcs.sub(['spectral']).wcs_pix2world(channels, 0)[0]
if reference_frequency is None:
reference_frequency = numpy.average(freq)
log.debug(
"calculate_image_from_frequency_moments: Reference frequency = %.3f (MHz)"
% (reference_frequency))
newim = copy_image(im)
newim.data[...] = 0.0
for moment in range(nmoments):
for chan in range(nchan):
weight = numpy.power(
(freq[chan] - reference_frequency) / reference_frequency,
moment)
newim.data[chan, ...] += moment_image.data[moment, ...] * weight
return newim
def update_skymodel_from_image(sm, im, damping=0.5):
"""Update a skymodel for an image
:param sm:
:param im:
:return:
"""
for i, th in enumerate(sm):
newim = copy_image(im)
if th.mask is not None:
newim.data *= th.mask.data
th.image.data += damping * newim.data
return sm
def calculate_skymodel_equivalent_image(sm):
"""Calculate an equivalent image for a skymodel
:param sm:
:return:
"""
combined_model = copy_image(sm[0].image)
combined_model.data[...] = 0.0
for th in sm:
if th.image is not None:
if th.mask is not None:
combined_model.data += th.mask.data * th.image.data
else:
combined_model.data += th.image.data
return combined_model
def ft_ift_sm(ov, sm, g):
assert isinstance(ov, Visibility) or isinstance(ov,
BlockVisibility), ov
assert isinstance(sm, SkyModel), sm
if g is not None:
assert len(g) == 2, g
assert isinstance(g[0], Image), g[0]
assert isinstance(g[1], ConvolutionFunction), g[1]
v = copy_visibility(ov)
v.data['vis'][...] = 0.0 + 0.0j
if len(sm.components) > 0:
if isinstance(sm.mask, Image):
comps = copy_skycomponent(sm.components)
comps = apply_beam_to_skycomponent(comps, sm.mask)
v = predict_skycomponent_visibility(v, comps)
else:
v = predict_skycomponent_visibility(v, sm.components)
if isinstance(sm.image, Image):
if numpy.max(numpy.abs(sm.image.data)) > 0.0:
if isinstance(sm.mask, Image):
model = copy_image(sm.image)
model.data *= sm.mask.data
else:
model = sm.image
v = predict_list_serial_workflow([v], [model],
context=context,
vis_slices=vis_slices,
facets=facets,
gcfcf=[g],
**kwargs)[0]
assert isinstance(sm.image, Image), sm.image
result = invert_list_serial_workflow([v], [sm.image],
context=context,
vis_slices=vis_slices,
facets=facets,
gcfcf=[g],
**kwargs)[0]
if isinstance(sm.mask, Image):
result[0].data *= sm.mask.data
return result
def deconvolve(dirty, psf, model, facet, gthreshold):
import time
starttime = time.time()
if prefix == '':
lprefix = "facet %d" % facet
else:
lprefix = "%s, facet %d" % (prefix, facet)
nmoments = get_parameter(kwargs, "nmoments", 0)
if nmoments > 0:
moment0 = calculate_image_frequency_moments(dirty)
this_peak = numpy.max(numpy.abs(
moment0.data[0, ...])) / dirty.data.shape[0]
else:
this_peak = numpy.max(numpy.abs(dirty.data[0, ...]))
if this_peak > 1.1 * gthreshold:
log.info(
"deconvolve_list_serial_workflow %s: cleaning - peak %.6f > 1.1 * threshold %.6f"
% (lprefix, this_peak, gthreshold))
kwargs['threshold'] = gthreshold
result, _ = deconvolve_cube(dirty, psf, prefix=lprefix, **kwargs)
if result.data.shape[0] == model.data.shape[0]:
result.data += model.data
else:
log.warning(
"deconvolve_list_serial_workflow %s: Initial model %s and clean result %s do not have the same shape"
% (lprefix, str(
model.data.shape[0]), str(result.data.shape[0])))
flux = numpy.sum(result.data[0, 0, ...])
log.info(
'### %s, %.6f, %.6f, True, %.3f # cycle, facet, peak, cleaned flux, clean, time?'
% (lprefix, this_peak, flux, time.time() - starttime))
return result
else:
log.info(
"deconvolve_list_serial_workflow %s: Not cleaning - peak %.6f <= 1.1 * threshold %.6f"
% (lprefix, this_peak, gthreshold))
log.info(
'### %s, %.6f, %.6f, False, %.3f # cycle, facet, peak, cleaned flux, clean, time?'
% (lprefix, this_peak, 0.0, time.time() - starttime))
return copy_image(model)
def deconvolve(dirty, psf, model, facet, gthreshold):
if prefix == '':
lprefix = "facet %d" % facet
else:
lprefix = "%s, facet %d" % (prefix, facet)
if nmoments > 0:
moment0 = calculate_image_frequency_moments(dirty)
this_peak = numpy.max(numpy.abs(
moment0.data[0, ...])) / dirty.data.shape[0]
else:
this_peak = numpy.max(numpy.abs(dirty.data[0, ...]))
if this_peak > 1.1 * gthreshold:
# log.info(
# "deconvolve_list_arlexecute_workflow %s: cleaning - peak %.6f > 1.1 * threshold %.6f" % (
# lprefix, this_peak,
# gthreshold))
kwargs['threshold'] = gthreshold
result, _ = deconvolve_cube(dirty, psf, prefix=lprefix, **kwargs)
if result.data.shape[0] == model.data.shape[0]:
result.data += model.data
# else:
# log.warning(
# "deconvolve_list_arlexecute_workflow %s: Initial model %s and clean result %s do not have the same shape" %
# (lprefix, str(model.data.shape[0]), str(result.data.shape[0])))
#
flux = numpy.sum(result.data[0, 0, ...])
# log.info('### %s, %.6f, %.6f, True, # cycle, facet, peak, cleaned flux, clean'
# % (lprefix, this_peak, flux[0]))
#
return result
else:
# log.info("deconvolve_list_arlexecute_workflow %s: Not cleaning - peak %.6f <= 1.1 * threshold %.6f" % (
# lprefix, this_peak,
# gthreshold))
# log.info('### %s, %.6f, %.6f, False, %.3f # cycle, facet, peak, cleaned flux, clean'
# % (lprefix, this_peak, 0.0))
return copy_image(model)
def initialize_skymodel_voronoi(model, comps, gt=None):
"""Create a skymodel by Voronoi partitioning of the components, fill with components
:param model: Model image
:param comps: Skycomponents
:param gt: Gaintable
:return:
"""
skymodel_images = list()
for i, mask in enumerate(image_voronoi_iter(model, comps)):
im = copy_image(model)
im.data *= mask.data
if gt is not None:
newgt = copy_gaintable(gt)
newgt.phasecentre = comps[i].direction
else:
newgt=None
skymodel_images.append(SkyModel(image=im, components=None, gaintable=newgt, mask=mask))
return skymodel_images
def ft_ift_sm(ov, sm):
assert isinstance(ov, Visibility), ov
v = copy_visibility(ov)
v.data['vis'][...] = 0.0 + 0.0j
if len(sm.components) > 0:
if isinstance(sm.mask, Image):
comps = copy_skycomponent(sm.components)
comps = apply_beam_to_skycomponent(comps, sm.mask)
v = predict_skycomponent_visibility(v, comps)
else:
v = predict_skycomponent_visibility(v, sm.components)
if isinstance(sm.image, Image):
if numpy.max(numpy.abs(sm.image.data)) > 0.0:
if isinstance(sm.mask, Image):
model = copy_image(sm.image)
model.data *= sm.mask.data
else:
model = sm.image
v = predict_list_serial_workflow([v], [model],
context=context,
vis_slices=vis_slices,
facets=facets,
gcfcf=gcfcf,
**kwargs)[0]
assert isinstance(sm.image, Image), sm.image
result = invert_list_serial_workflow([v], [sm.image],
context=context,
vis_slices=vis_slices,
facets=facets,
gcfcf=gcfcf,
**kwargs)[0]
if isinstance(sm.mask, Image):
result[0].data *= sm.mask.data
return result
def show_skymodel(sms, psf_width=1.75, cm='Greys', vmax=None, vmin=None):
sp = 1
for ism, sm in enumerate(sms):
plt.clf()
plt.subplot(121, projection=sms[ism].image.wcs.sub([1, 2]))
sp += 1
smodel = copy_image(sms[ism].image)
smodel = insert_skycomponent(smodel, sms[ism].components)
smodel = smooth_image(smodel, psf_width)
if vmax is None:
vmax = numpy.max(smodel.data[0, 0, ...])
if vmin is None:
vmin = numpy.min(smodel.data[0, 0, ...])
plt.imshow(smodel.data[0, 0, ...], origin='lower', cmap=cm, vmax=vmax, vmin=vmin)
plt.xlabel(sms[ism].image.wcs.wcs.ctype[0])
plt.ylabel(sms[ism].image.wcs.wcs.ctype[1])
plt.title('SkyModel%d' % ism)
components = sms[ism].components
if components is not None:
for sc in components:
x, y = skycoord_to_pixel(sc.direction, sms[ism].image.wcs, 0, 'wcs')
plt.plot(x, y, marker='+', color='red')
gaintable = sms[ism].gaintable
if gaintable is not None:
plt.subplot(122)
sp += 1
phase = numpy.angle(sm.gaintable.gain[:, :, 0, 0, 0])
phase -= phase[:, 0][:, numpy.newaxis]
plt.imshow(phase, origin='lower')
plt.xlabel('Dish/Station')
plt.ylabel('Integration')
plt.show()
marker='.',
label='Original')
plt.semilogy(numpy.arange(len(ical_fluxes)),
ical_fluxes,
marker='.',
label='ICAL')
plt.semilogy(numpy.arange(len(mpccal_fluxes)),
mpccal_fluxes,
marker='.',
label='MPCCAL')
plt.title('All component fluxes')
plt.ylabel('Flux (Jy)')
plt.legend()
plt.show(block=block_plots)
difference_image = copy_image(mpccal_restored)
difference_image.data -= ical_restored.data
print(qa_image(difference_image, context='MPCCAL - ICAL image'))
show_image(difference_image,
title='MPCCAL - ICAL image',
components=ical_components)
plt.show(block=block_plots)
export_image_to_fits(
difference_image,
arl_path(
'test_results/low-sims-mpc-mpccal-ical-restored_%.1frmax.fits' %
rmax))
newscreen = create_empty_image_like(screen)
gaintables = [sm.gaintable for sm in mpccal_skymodel]
def create_awterm_convolutionfunction(im,
make_pb=None,
nw=1,
wstep=1e15,
oversampling=8,
support=6,
use_aaf=True,
maxsupport=512):
""" Fill AW projection kernel into a GridData.
:param im: Image template
:param make_pb: Function to make the primary beam model image
:param nw: Number of w planes
:param wstep: Step in w (wavelengths)
:param oversampling: Oversampling of the convolution function in uv space
:return: griddata correction Image, griddata kernel as GridData
"""
d2r = numpy.pi / 180.0
# We only need the griddata correction function for the PSWF so we make
# it for the shape of the image
nchan, npol, ony, onx = im.data.shape
assert isinstance(im, Image)
# Calculate the template convolution kernel.
cf = create_convolutionfunction_from_image(im,
oversampling=oversampling,
support=support)
cf_shape = list(cf.data.shape)
cf_shape[2] = nw
cf.data = numpy.zeros(cf_shape).astype('complex')
cf.grid_wcs.wcs.crpix[4] = nw // 2 + 1.0
cf.grid_wcs.wcs.cdelt[4] = wstep
cf.grid_wcs.wcs.ctype[4] = 'WW'
if numpy.abs(wstep) > 0.0:
w_list = cf.grid_wcs.sub([5]).wcs_pix2world(range(nw), 0)[0]
else:
w_list = [0.0]
assert isinstance(oversampling, int)
assert oversampling > 0
nx = max(maxsupport, 2 * oversampling * support)
ny = max(maxsupport, 2 * oversampling * support)
qnx = nx // oversampling
qny = ny // oversampling
cf.data[...] = 0.0
subim = copy_image(im)
ccell = onx * numpy.abs(d2r * subim.wcs.wcs.cdelt[0]) / qnx
subim.data = numpy.zeros([nchan, npol, qny, qnx])
subim.wcs.wcs.cdelt[0] = -ccell / d2r
subim.wcs.wcs.cdelt[1] = +ccell / d2r
subim.wcs.wcs.crpix[0] = qnx // 2 + 1.0
subim.wcs.wcs.crpix[1] = qny // 2 + 1.0
if use_aaf:
this_pswf_gcf, _ = create_pswf_convolutionfunction(subim,
oversampling=1,
support=6)
norm = 1.0 / this_pswf_gcf.data
else:
norm = 1.0
if make_pb is not None:
pb = make_pb(subim)
rpb, footprint = reproject_image(pb, subim.wcs, shape=subim.shape)
rpb.data[footprint.data < 1e-6] = 0.0
norm *= rpb.data
# We might need to work with a larger image
padded_shape = [nchan, npol, ny, nx]
thisplane = copy_image(subim)
thisplane.data = numpy.zeros(thisplane.shape, dtype='complex')
for z, w in enumerate(w_list):
thisplane.data[...] = 0.0 + 0.0j
thisplane = create_w_term_like(thisplane, w, dopol=True)
thisplane.data *= norm
paddedplane = pad_image(thisplane, padded_shape)
paddedplane = fft_image(paddedplane)
ycen, xcen = ny // 2, nx // 2
for y in range(oversampling):
ybeg = y + ycen + (support * oversampling) // 2 - oversampling // 2
yend = y + ycen - (support * oversampling) // 2 - oversampling // 2
vv = range(ybeg, yend, -oversampling)
for x in range(oversampling):
xbeg = x + xcen + (support *
oversampling) // 2 - oversampling // 2
xend = x + xcen - (support *
oversampling) // 2 - oversampling // 2
uu = range(xbeg, xend, -oversampling)
for chan in range(nchan):
for pol in range(npol):
cf.data[chan, pol, z, y, x, :, :] = paddedplane.data[
chan, pol, :, :][vv, :][:, uu]
cf.data /= numpy.sum(
numpy.real(cf.data[0, 0, nw // 2, oversampling // 2,
oversampling // 2, :, :]))
cf.data = numpy.conjugate(cf.data)
if use_aaf:
pswf_gcf, _ = create_pswf_convolutionfunction(im,
oversampling=1,
support=6)
else:
pswf_gcf = create_empty_image_like(im)
pswf_gcf.data[...] = 1.0
return pswf_gcf, cf
def create_awterm_convolutionfunction(im,
make_pb=None,
nw=1,
wstep=1e15,
oversampling=8,
support=6,
use_aaf=True,
maxsupport=512,
**kwargs):
""" Fill AW projection kernel into a GridData.
:param im: Image template
:param make_pb: Function to make the primary beam model image (hint: use a partial)
:param nw: Number of w planes
:param wstep: Step in w (wavelengths)
:param oversampling: Oversampling of the convolution function in uv space
:return: griddata correction Image, griddata kernel as GridData
"""
d2r = numpy.pi / 180.0
# We only need the griddata correction function for the PSWF so we make
# it for the shape of the image
nchan, npol, ony, onx = im.data.shape
assert isinstance(im, Image)
# Calculate the template convolution kernel.
cf = create_convolutionfunction_from_image(im,
oversampling=oversampling,
support=support)
cf_shape = list(cf.data.shape)
cf_shape[2] = nw
cf.data = numpy.zeros(cf_shape).astype('complex')
cf.grid_wcs.wcs.crpix[4] = nw // 2 + 1.0
cf.grid_wcs.wcs.cdelt[4] = wstep
cf.grid_wcs.wcs.ctype[4] = 'WW'
if numpy.abs(wstep) > 0.0:
w_list = cf.grid_wcs.sub([5]).wcs_pix2world(range(nw), 0)[0]
else:
w_list = [0.0]
assert isinstance(oversampling, int)
assert oversampling > 0
nx = max(maxsupport, 2 * oversampling * support)
ny = max(maxsupport, 2 * oversampling * support)
qnx = nx // oversampling
qny = ny // oversampling
cf.data[...] = 0.0
subim = copy_image(im)
ccell = onx * numpy.abs(d2r * subim.wcs.wcs.cdelt[0]) / qnx
subim.data = numpy.zeros([nchan, npol, qny, qnx])
subim.wcs.wcs.cdelt[0] = -ccell / d2r
subim.wcs.wcs.cdelt[1] = +ccell / d2r
subim.wcs.wcs.crpix[0] = qnx // 2 + 1.0
subim.wcs.wcs.crpix[1] = qny // 2 + 1.0
if use_aaf:
this_pswf_gcf, _ = create_pswf_convolutionfunction(subim,
oversampling=1,
support=6)
norm = 1.0 / this_pswf_gcf.data
else:
norm = 1.0
if make_pb is not None:
pb = make_pb(subim)
rpb, footprint = reproject_image(pb, subim.wcs, shape=subim.shape)
rpb.data[footprint.data < 1e-6] = 0.0
norm *= rpb.data
# We might need to work with a larger image
padded_shape = [nchan, npol, ny, nx]
thisplane = copy_image(subim)
thisplane.data = numpy.zeros(thisplane.shape, dtype='complex')
for z, w in enumerate(w_list):
thisplane.data[...] = 0.0 + 0.0j
thisplane = create_w_term_like(thisplane, w, dopol=True)
thisplane.data *= norm
paddedplane = pad_image(thisplane, padded_shape)
paddedplane = fft_image(paddedplane)
ycen, xcen = ny // 2, nx // 2
for y in range(oversampling):
ybeg = y + ycen + (support * oversampling) // 2 - oversampling // 2
yend = y + ycen - (support * oversampling) // 2 - oversampling // 2
# vv = range(ybeg, yend, -oversampling)
for x in range(oversampling):
xbeg = x + xcen + (support *
oversampling) // 2 - oversampling // 2
xend = x + xcen - (support *
oversampling) // 2 - oversampling // 2
# uu = range(xbeg, xend, -oversampling)
cf.data[..., z, y,
x, :, :] = paddedplane.data[...,
ybeg:yend:-oversampling,
xbeg:xend:-oversampling]
# for chan in range(nchan):
# for pol in range(npol):
# cf.data[chan, pol, z, y, x, :, :] = paddedplane.data[chan, pol, :, :][vv, :][:, uu]
cf.data /= numpy.sum(
numpy.real(cf.data[0, 0, nw // 2, oversampling // 2,
oversampling // 2, :, :]))
cf.data = numpy.conjugate(cf.data)
#====================================
#Use ASKAPSoft routine to crop the support size
crop_ASKAPSOft_like = True
if crop_ASKAPSOft_like:
#Hardcode the cellsize: 1 / FOV
#uv_cellsize = 57.3;#N=1200 pixel and pixelsize is 3 arcseconds
#uv_cellsize = 43.97;#N=1600 pixel and pixelsize is 3 arcseconds
#uv_cellsize = 114.6;#N=1800 pixel with 1 arcsecond pixelsize
#uv_cellsize = 57.3;#N=1800 pixel with 2 arcsecond pixelsize
#uv_cellsize = 1145.91509915;#N=1800 pixxel with 0.1 arcsecond pixelsize
#Get from **kwargs
if kwargs is None:
#Safe solution works for baselines up to > 100km and result in small kernels
uv_cellsize = 1145.91509915
#N=1800 pixxel with 0.1 arcsecond pixelsize
if 'UVcellsize' in kwargs.keys():
uv_cellsize = kwargs['UVcellsize']
#print(uv_cellsize);
#Cutoff param in ASKAPSoft hardcoded as well
ASKAPSoft_cutof = 0.1
wTheta_list = numpy.zeros(len(w_list))
for i in range(0, len(w_list)):
if w_list[i] == 0:
wTheta_list[i] = 0.9
#This is due to the future if statements cause if it is small, the kernel will be 3 which is a clear cutoff
else:
wTheta_list[i] = numpy.fabs(
w_list[i]) / (uv_cellsize * uv_cellsize)
kernel_size_list = []
#We rounded the kernels according to conventional rounding rules
for i in range(0, len(wTheta_list)):
#if wTheta_list[i] < 1:
if wTheta_list[i] < 1: #Change to ASKAPSoft
kernel_size_list.append(int(3.))
elif ASKAPSoft_cutof < 0.01:
kernel_size_list.append(int(6 + 1.14 * wTheta_list[i]))
else:
kernel_size_list.append(
int(numpy.sqrt(49 + wTheta_list[i] * wTheta_list[i])))
log.info('W-kernel w-terms:')
log.info(w_list)
log.info('Corresponding w-kernel sizes:')
log.info(kernel_size_list)
print(numpy.unique(kernel_size_list))
#print(kernel_size_list);
crop_list = []
#another rounding according to conventional rounding rules
for i in range(0, len(kernel_size_list)):
if support - kernel_size_list[i] <= 0:
crop_list.append(int(0))
else:
crop_list.append(int((support - kernel_size_list[i]) / 2))
#Crop original suppor
for i in range(0, nw):
if crop_list[i] != 0:
cf.data[0, 0, i, :, :, 0:crop_list[i], :] = 0
cf.data[0, 0, i, :, :, -crop_list[i]:, :] = 0
cf.data[0, 0, i, :, :, :, 0:crop_list[i]] = 0
cf.data[0, 0, i, :, :, :, -crop_list[i]:] = 0
else:
pass
#Plot
#import matplotlib.pyplot as plt
#cf.data[0,0,i,0,0,...][cf.data[0,0,i,0,0,...] != 0.] = 1+0.j;
#plt.imshow(numpy.real(cf.data[0,0,i,0,0,...]))
#plt.show(block=True)
#plt.close();
#====================================
if use_aaf:
pswf_gcf, _ = create_pswf_convolutionfunction(im,
oversampling=1,
support=6)
else:
pswf_gcf = create_empty_image_like(im)
pswf_gcf.data[...] = 1.0
return pswf_gcf, cf
def sum_images(imagelist):
out = copy_image(imagelist[0])
out.data += imagelist[1].data
return out
def ingest_visibility(self,
freq=None,
chan_width=None,
times=None,
add_errors=False,
block=True,
bandpass=False):
if freq is None:
freq = [1e8]
if chan_width is None:
chan_width = [1e6]
if times is None:
times = (numpy.pi / 12.0) * numpy.linspace(-3.0, 3.0, 5)
lowcore = create_named_configuration('LOWBD2', rmax=750.0)
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=frequency,
phasecentre=phasecentre,
polarisation_frame=PolarisationFrame("stokesI"))
nchan = len(self.frequency)
flux = numpy.array(nchan * [[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(
direction=sc,
flux=flux,
frequency=frequency,
polarisation_frame=PolarisationFrame("stokesI"))
comps.append(comp)
if block:
predict_skycomponent_visibility(vt, comps)
else:
predict_skycomponent_visibility(vt, comps)
insert_skycomponent(model, comps)
self.comps = comps
self.model = copy_image(model)
self.empty_model = create_empty_image_like(model)
export_image_to_fits(
model, '%s/test_pipeline_functions_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)
if bandpass:
bgt = create_gaintable_from_blockvisibility(vt, timeslice=1e5)
bgt = simulate_gaintable(bgt,
phase_error=0.01,
amplitude_error=0.01,
smooth_channels=4)
vt = apply_gaintable(vt, bgt)
return vt
plt.show()
plt.clf()
show_image(im, chan=noise_channel)
plt.title('Noise image %s' % (basename))
plt.savefig('simulation_noise_channel_%d.png' % signal_channel)
plt.show()
print(im)
imfft = fft_image(im)
print(imfft)
omega = numpy.pi * resolution**2 / (4 * numpy.log(2.0))
wavelength = consts.c / numpy.average(im.frequency)
kperjy = 1e-26 * wavelength**2 / (2 * consts.k_B * omega)
im_spectrum = copy_image(imfft)
im_spectrum.data = kperjy.value * numpy.abs(imfft.data)
plt.clf()
show_image(im_spectrum,
chan=signal_channel,
vmax=0.01 * numpy.max(im_spectrum.data[signal_channel, ...]))
plt.gca().set_title("Amplitude(FFT(image)) %s" % (basename))
plt.tight_layout()
plt.savefig('power_spectrum_image_channel_%d.png' % signal_channel)
plt.show()
noisy = numpy.max(im_spectrum.data[noise_channel, 0]) > 0.0
if noisy:
plt.clf()
show_image(im_spectrum,
chan=noise_channel,
vmax=0.01 * numpy.max(im_spectrum.data[noise_channel, ...]))
zernikes = list()
default_vp = create_vp_generic_numeric(model, pointingcentre=None, diameter=15.0, blockage=0.0,
taper='gaussian',
edge=0.03162278, padding=2, use_local=True)
key_nolls = [3, 5, 6, 7]
for noll in key_nolls:
zernike = {'coeff': 1.0, 'noll': noll}
zernike['vp'] = create_vp_generic_numeric(model, pointingcentre=None, diameter=15.0, blockage=0.0,
taper='gaussian',
edge=0.03162278, zernikes=[zernike], padding=2, use_local=True)
zernikes.append(zernike)
for trial in range(ntrials):
coeffs = numpy.random.normal(0.0, 0.03, len(key_nolls))
vp = copy_image(default_vp)
for i in range(len(key_nolls)):
vp.data += coeffs[i] * zernikes[i]['vp'].data
vp.data = vp.data / numpy.max(numpy.abs(vp.data))
vp_data = vp.data / numpy.max(numpy.abs(vp.data))
vp.data = numpy.real(vp_data)
print(trial, qa_image(vp))
export_image_to_fits(vp, "%s/test_voltage_pattern_real_%s_trial%d.fits" % (dir, 'MID_RANDOM_ZERNIKES', trial))
row = (trial - 1) // 4
col = (trial - 1) - 4 * row
ax = axs[row, col]
ax.imshow(vp.data[0, 0], vmax=0.01, vmin=-0.001)
# ax.set_title('Noll %d' % noll)
ax.axis('off')
plt.ylabel('Amp Visibility')
plt.title('Field %d' % (field))
plt.show()
cellsize = 0.00001
model = create_image_from_visibility(
vis_list[0],
cellsize=cellsize,
npixel=512,
nchan=1,
frequency=[0.5 * (8435100000.0 + 8.4851e+09)],
channel_bandwidth=[1e8],
imagecentre=vis_list[0].phasecentre,
polarisation_frame=PolarisationFrame('stokesIQUV'))
mosaic = copy_image(model)
mosaicsens = copy_image(model)
work = copy_image(model)
for vt in vis_list:
channel_model = create_image_from_visibility(
vt,
cellsize=cellsize,
npixel=512,
nchan=1,
imagecentre=vis_list[0].phasecentre,
polarisation_frame=PolarisationFrame('stokesIQUV'))
beam = create_pb(channel_model,
telescope='VLA',
pointingcentre=vt.phasecentre,
# In[8]:
show_image(beam,
components=all_components,
cm='Greys',
title='Primary beam plus all components',
vmax=3.0)
lprint("Number of components %d" % len(all_components))
# ### Now show all components with color denoting the nearest bright component, and an image with each pixel filled with the index of the nearest bright component
# In[9]:
vor, vor_array = voronoi_decomposition(beam, filtered_bright_components)
vor_image = copy_image(beam)
vor_image.data[...] = vor_array
show_image(
vor_image,
cm='Greys',
title='Voronoi partitioning with all components shown, contour at 10% beam',
vmax=3 * numpy.max(vor_array))
comps_lists = partition_skycomponent_neighbours(all_components,
filtered_bright_components)
for comp_id, comps in enumerate(comps_lists):
flux = numpy.sum([c.flux[0, 0] for c in comps])
directions = SkyCoord([u.rad * c.direction.ra.rad for c in comps],
[u.rad * c.direction.dec.rad for c in comps])