def test_griddata_invert_awterm(self): self.actualSetUp(zerow=False) make_pb = functools.partial(create_pb_generic, diameter=35.0, blockage=0.0, use_local=False) pb = make_pb(self.model) if self.persist: export_image_to_fits(pb, "%s/test_gridding_awterm_pb.fits" % self.dir) gcf, cf = create_awterm_convolutionfunction(self.model, make_pb=make_pb, nw=100, wstep=8.0, oversampling=16, support=32, use_aaf=True) cf_image = convert_convolutionfunction_to_image(cf) cf_image.data = numpy.real(cf_image.data) if self.persist: export_image_to_fits(cf_image, "%s/test_gridding_awterm_cf.fits" % self.dir) griddata = create_griddata_from_image(self.model, nw=100, wstep=8.0) griddata, sumwt = grid_visibility_to_griddata(self.vis, griddata=griddata, cf=cf) im = fft_griddata_to_image(griddata, gcf) im = normalize_sumwt(im, sumwt) if self.persist: export_image_to_fits( im, '%s/test_gridding_dirty_awterm.fits' % self.dir) self.check_peaks(im, 97.13240677427714)
def test_griddata_invert_aterm_noover(self): self.actualSetUp(zerow=True) make_pb = functools.partial(create_pb_generic, diameter=35.0, blockage=0.0, use_local=False) pb = make_pb(self.model) if self.persist: export_image_to_fits(pb, "%s/test_gridding_aterm_pb.fits" % self.dir) gcf, cf = create_awterm_convolutionfunction(self.model, make_pb=make_pb, nw=1, oversampling=1, support=16, use_aaf=True) griddata = create_griddata_from_image(self.model) griddata, sumwt = grid_visibility_to_griddata(self.vis, griddata=griddata, cf=cf) im = fft_griddata_to_image(griddata, gcf) im = normalize_sumwt(im, sumwt) if self.persist: export_image_to_fits( im, '%s/test_gridding_dirty_aterm_noover.fits' % self.dir) self.check_peaks(im, 97.10594988491549)
def test_griddata_invert_wterm(self): self.actualSetUp(zerow=False) gcf, cf = create_awterm_convolutionfunction(self.model, nw=100, wstep=8.0, oversampling=8, support=32, use_aaf=True) cf_image = convert_convolutionfunction_to_image(cf) cf_image.data = numpy.real(cf_image.data) if self.persist: export_image_to_fits(cf_image, "%s/test_gridding_wterm_cf.fits" % self.dir) griddata = create_griddata_from_image(self.model, nw=1) griddata, sumwt = grid_visibility_to_griddata(self.vis, griddata=griddata, cf=cf) im = fft_griddata_to_image(griddata, gcf) im = normalize_sumwt(im, sumwt) if self.persist: export_image_to_fits( im, '%s/test_gridding_dirty_wterm.fits' % self.dir) self.check_peaks(im, 97.13215242859648)
def sum_invert_results(image_list): """ Sum a set of invert results with appropriate weighting :param image_list: List of [image, sum weights] pairs :return: image, sum of weights """ if len(image_list) == 1: return image_list[0] first = True sumwt = 0.0 im = None for i, arg in enumerate(image_list): if arg is not None: if isinstance(arg[1], numpy.ndarray): scale = arg[1][..., numpy.newaxis, numpy.newaxis] else: scale = arg[1] if first: im = copy_image(arg[0]) im.data *= scale sumwt = arg[1] first = False else: im.data += scale * arg[0].data sumwt += arg[1] assert not first, "No invert results" im = normalize_sumwt(im, sumwt) return im, sumwt
def test_griddata_invert_fast(self): self.actualSetUp(zerow=True) gcf, cf = create_box_convolutionfunction(self.model) griddata = create_griddata_from_image(self.model) griddata, sumwt = grid_visibility_to_griddata(self.vis, griddata=griddata, cf=cf) im = fft_griddata_to_image(griddata, gcf) im = normalize_sumwt(im, sumwt) export_image_to_fits(im, '%s/test_gridding_dirty_fast.fits' % self.dir) self.check_peaks(im, 96.74492791536595, tol=1e-7)
def test_griddata_invert_pswf_w(self): self.actualSetUp(zerow=False) gcf, cf = create_pswf_convolutionfunction(self.model, support=6, oversampling=32) griddata = create_griddata_from_image(self.model) griddata, sumwt = grid_visibility_to_griddata(self.vis, griddata=griddata, cf=cf) im = fft_griddata_to_image(griddata, gcf) im = normalize_sumwt(im, sumwt) export_image_to_fits(im, '%s/test_gridding_dirty_pswf_w.fits' % self.dir) self.check_peaks(im, 96.62754566597258, tol=1e-7)
def invert_serial(vis, im: Image, dopsf=False, normalize=True, context='2d', vis_slices=1, facets=1, overlap=0, taper=None, **kwargs): """ Invert using algorithm specified by context: * 2d: Two-dimensional transform * wstack: wstacking with either vis_slices or wstack (spacing between w planes) set * wprojection: w projection with wstep (spacing between w places) set, also kernel='wprojection' * timeslice: snapshot imaging with either vis_slices or timeslice set. timeslice='auto' does every time * facets: Faceted imaging with facets facets on each axis * facets_wprojection: facets AND wprojection * facets_wstack: facets AND wstacking * wprojection_wstack: wprojection and wstacking :param vis: :param im: :param dopsf: Make the psf instead of the dirty image (False) :param normalize: Normalize by the sum of weights (True) :param context: Imaging context e.g. '2d', 'timeslice', etc. :param kwargs: :return: Image, sum of weights """ c = imaging_context(context) vis_iter = c['vis_iterator'] invert = c['invert'] if not isinstance(vis, Visibility): svis = convert_blockvisibility_to_visibility(vis) else: svis = vis resultimage = create_empty_image_like(im) totalwt = None for rows in vis_iter(svis, vis_slices=vis_slices): if numpy.sum(rows): visslice = create_visibility_from_rows(svis, rows) sumwt = 0.0 workimage = create_empty_image_like(im) for dpatch in image_scatter_facets(workimage, facets=facets, overlap=overlap, taper=taper): result, sumwt = invert(visslice, dpatch, dopsf, normalize=False, facets=facets, vis_slices=vis_slices, **kwargs) # Ensure that we fill in the elements of dpatch instead of creating a new numpy arrray dpatch.data[...] = result.data[...] # Assume that sumwt is the same for all patches if totalwt is None: totalwt = sumwt else: totalwt += sumwt resultimage.data += workimage.data assert totalwt is not None, "No valid data found for imaging" if normalize: resultimage = normalize_sumwt(resultimage, totalwt) return resultimage, totalwt
def test_griddata_invert_box(self): self.actualSetUp(zerow=True) gcf, cf = create_box_convolutionfunction(self.model) griddata = create_griddata_from_image(self.model) griddata, sumwt = grid_visibility_to_griddata(self.vis, griddata=griddata, cf=cf) im = fft_griddata_to_image(griddata, gcf) im = normalize_sumwt(im, sumwt) if self.persist: export_image_to_fits(im, '%s/test_gridding_dirty_box.fits' % self.dir) self.check_peaks(im, 97.11833094588997, tol=1e-7)
def test_griddata_invert_pswf(self): self.actualSetUp(zerow=True) gcf, cf = create_pswf_convolutionfunction(self.model, support=6, oversampling=32) griddata = create_griddata_from_image(self.model) griddata, sumwt = grid_visibility_to_griddata(self.vis, griddata=griddata, cf=cf) im = fft_griddata_to_image(griddata, gcf) im = normalize_sumwt(im, sumwt) if self.persist: export_image_to_fits(im, '%s/test_gridding_dirty_pswf.fits' % self.dir) self.check_peaks(im, 97.00435128311616, tol=1e-7)
def test_griddata_weight(self): self.actualSetUp(zerow=True) gcf, cf = create_box_convolutionfunction(self.model) gd = create_griddata_from_image(self.model) gd_list = [grid_weight_to_griddata(self.vis, gd, cf) for i in range(10)] gd, sumwt = griddata_merge_weights(gd_list, algorithm='uniform') self.vis = griddata_reweight(self.vis, gd, cf) gd, sumwt = grid_visibility_to_griddata(self.vis, griddata=gd, cf=cf) im = fft_griddata_to_image(gd, gcf) im = normalize_sumwt(im, sumwt) if self.persist: export_image_to_fits(im, '%s/test_gridding_dirty_2d_uniform.fits' % self.dir) self.check_peaks(im, 99.42031190701735)
def sum_invert_results(image_list, normalize=True): """ Sum a set of invert results with appropriate weighting :param image_list: List of [image, sum weights] pairs :return: image, sum of weights """ if len(image_list) == 1: return image_list[0] im = create_empty_image_like(image_list[0][0]) sumwt = image_list[0][1].copy() sumwt *= 0.0 for i, arg in enumerate(image_list): if arg is not None: im.data += arg[1][..., numpy.newaxis, numpy.newaxis] * arg[0].data sumwt += arg[1] if normalize: im = normalize_sumwt(im, sumwt) return im, sumwt
def invert_ng(bvis: BlockVisibility, model: Image, dopsf: bool = False, normalize: bool = True, **kwargs) -> (Image, numpy.ndarray): """ Invert using nifty-gridder module https://gitlab.mpcdf.mpg.de/ift/nifty_gridder Use the image im as a template. Do PSF in a separate call. This is at the bottom of the layering i.e. all transforms are eventually expressed in terms of this function. . Any shifting needed is performed here. :param bvis: BlockVisibility to be inverted :param im: image template (not changed) :param normalize: Normalize by the sum of weights (True) :return: (resulting image, sum of the weights for each frequency and polarization) """ assert isinstance(bvis, BlockVisibility), bvis im = copy_image(model) nthreads = get_parameter(kwargs, "threads", 4) epsilon = get_parameter(kwargs, "epsilon", 1e-12) do_wstacking = get_parameter(kwargs, "do_wstacking", True) verbosity = get_parameter(kwargs, "verbosity", 0) sbvis = copy_visibility(bvis) sbvis = shift_vis_to_image(sbvis, im, tangent=True, inverse=False) vis = bvis.vis freq = sbvis.frequency # frequency, Hz nrows, nants, _, vnchan, vnpol = vis.shape uvw = sbvis.uvw.reshape([nrows * nants * nants, 3]) ms = vis.reshape([nrows * nants * nants, vnchan, vnpol]) wgt = sbvis.imaging_weight.reshape( [nrows * nants * nants, vnchan, vnpol]) if dopsf: ms[...] = 1.0 + 0.0j if epsilon > 5.0e-6: ms = ms.astype("c8") wgt = wgt.astype("f4") # Find out the image size/resolution npixdirty = im.nwidth pixsize = numpy.abs(numpy.radians(im.wcs.wcs.cdelt[0])) fuvw = uvw.copy() # We need to flip the u and w axes. fuvw[:, 0] *= -1.0 fuvw[:, 2] *= -1.0 nchan, npol, ny, nx = im.shape im.data[...] = 0.0 sumwt = numpy.zeros([nchan, npol]) ms = convert_pol_frame(ms, bvis.polarisation_frame, im.polarisation_frame, polaxis=2) # There's a latent problem here with the weights. # wgt = numpy.real(convert_pol_frame(wgt, bvis.polarisation_frame, im.polarisation_frame, polaxis=2)) # Set up the conversion from visibility channels to image channels vis_to_im = numpy.round(model.wcs.sub([4]).wcs_world2pix( freq, 0)[0]).astype('int') for vchan in range(vnchan): ichan = vis_to_im[vchan] for pol in range(npol): # Nifty gridder likes to receive contiguous arrays ms_1d = numpy.array([ ms[row, vchan:vchan + 1, pol] for row in range(nrows * nants * nants) ], dtype='complex') ms_1d.reshape([ms_1d.shape[0], 1]) wgt_1d = numpy.array([ wgt[row, vchan:vchan + 1, pol] for row in range(nrows * nants * nants) ]) wgt_1d.reshape([wgt_1d.shape[0], 1]) dirty = ng.ms2dirty(fuvw, freq[vchan:vchan + 1], ms_1d, wgt_1d, npixdirty, npixdirty, pixsize, pixsize, epsilon, do_wstacking=do_wstacking, nthreads=nthreads, verbosity=verbosity) sumwt[ichan, pol] += numpy.sum(wgt[:, vchan, pol]) im.data[ichan, pol] += dirty.T if normalize: im = normalize_sumwt(im, sumwt) return im, sumwt