Source code for ngcasa.imaging.make_image_with_gcf

#  CASA Next Generation Infrastructure
#  Copyright (C) 2021 AUI, Inc. Washington DC, USA
#
#  This program is free software: you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
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#  You should have received a copy of the GNU General Public License
#  along with this program.  If not, see <https://www.gnu.org/licenses/>.
"""
this module will be included in the api
"""

[docs]def make_image_with_gcf(mxds, gcf_dataset, img_dataset, grid_parms, norm_parms, vis_sel_parms, img_sel_parms): """ Creates a cube or continuum dirty image from the user specified visibility, uvw and imaging weight data. A gridding convolution function (gcf_dataset), primary beam image (img_dataset) and a primary beam weight image (img_dataset) must be supplied. Parameters ---------- vis_dataset : xarray.core.dataset.Dataset Input visibility dataset. gcf_dataset : xarray.core.dataset.Dataset Input gridding convolution dataset. img_dataset : xarray.core.dataset.Dataset Input image dataset. grid_parms : dictionary grid_parms['image_size'] : list of int, length = 2 The image size (no padding). grid_parms['cell_size'] : list of number, length = 2, units = arcseconds The image cell size. grid_parms['chan_mode'] : {'continuum'/'cube'}, default = 'continuum' Create a continuum or cube image. grid_parms['fft_padding'] : number, acceptable range [1,100], default = 1.2 The factor that determines how much the gridded visibilities are padded before the fft is done. norm_parms : dictionary norm_parms['norm_type'] : {'none'/'flat_noise'/'flat_sky'}, default = 'flat_sky' Gridded (and FT'd) images represent the PB-weighted sky image. Qualitatively it can be approximated as two instances of the PB applied to the sky image (one naturally present in the data and one introduced during gridding via the convolution functions). normtype='flat_noise' : Divide the raw image by sqrt(sel_parms['weight_pb']) so that the input to the minor cycle represents the product of the sky and PB. The noise is 'flat' across the region covered by each PB. normtype='flat_sky' : Divide the raw image by sel_parms['weight_pb'] so that the input to the minor cycle represents only the sky. The noise is higher in the outer regions of the primary beam where the sensitivity is low. normtype='none' : No normalization after gridding and FFT. sel_parms : dictionary sel_parms['uvw'] : str, default ='UVW' The name of uvw data variable that will be used to grid the visibilities. sel_parms['data'] : str, default = 'DATA' The name of the visibility data to be gridded. sel_parms['imaging_weight'] : str, default ='IMAGING_WEIGHT' The name of the imaging weights to be used. sel_parms['image'] : str, default ='IMAGE' The created image name. sel_parms['sum_weight'] : str, default ='SUM_WEIGHT' The created sum of weights name. sel_parms['pb'] : str, default ='PB' The primary beam image to use for normalization. sel_parms['weight_pb'] : str, default ='WEIGHT_PB' The primary beam weight image to use for normalization. Returns ------- image_dataset : xarray.core.dataset.Dataset The image_dataset will contain the image created and the sum of weights. """ print('######################### Start make_image_with_gcf #########################') import numpy as np from numba import jit import time import math import dask.array.fft as dafft import xarray as xr import dask.array as da import matplotlib.pylab as plt import dask import copy, os from numcodecs import Blosc from itertools import cycle from cngi._utils._check_parms import _check_sel_parms, _check_existence_sel_parms from ._imaging_utils._check_imaging_parms import _check_grid_parms, _check_norm_parms #from ._imaging_utils._gridding_convolutional_kernels import _create_prolate_spheroidal_kernel, _create_prolate_spheroidal_kernel_1D from ._imaging_utils._standard_grid import _graph_standard_grid from ._imaging_utils._remove_padding import _remove_padding from ._imaging_utils._aperture_grid import _graph_aperture_grid from ._imaging_utils._normalize import _normalize from cngi.image import make_empty_sky_image #Deep copy so that inputs are not modified _mxds = mxds.copy(deep=True) _img_dataset = img_dataset.copy(deep=True) _vis_sel_parms = copy.deepcopy(vis_sel_parms) _img_sel_parms = copy.deepcopy(img_sel_parms) _grid_parms = copy.deepcopy(grid_parms) _norm_parms = copy.deepcopy(norm_parms) ##############Parameter Checking and Set Defaults############## assert('xds' in _vis_sel_parms), "######### ERROR: xds must be specified in sel_parms" #Can't have a default since xds names are not fixed. _vis_dataset = _mxds.attrs[_vis_sel_parms['xds']] assert(_check_grid_parms(_grid_parms)), "######### ERROR: grid_parms checking failed" assert(_check_norm_parms(_norm_parms)), "######### ERROR: norm_parms checking failed" #Check vis data_group _check_sel_parms(_vis_dataset,_vis_sel_parms) #Check img data_group _check_sel_parms(_img_dataset,_img_sel_parms,new_or_modified_data_variables={'sum_weight':'SUM_WEIGHT','image':'IMAGE'},required_data_variables={'pb':'PB','weight_pb':'WEIGHT_PB'},append_to_in_id=False) #'pb':'PB','weight_pb':'WEIGHT_PB', #print('did this work',_img_sel_parms) # assert(_check_sel_parms(_sel_parms,{'uvw':'UVW','data':'DATA','imaging_weight':'IMAGING_WEIGHT','sum_weight':'SUM_WEIGHT','image':'IMAGE','pb':'PB','weight_pb':'WEIGHT_PB'})), "######### ERROR: sel_parms checking failed" # assert(_check_existence_sel_parms(vis_dataset,{'uvw':_sel_parms['uvw'],'data':_sel_parms['data'],'imaging_weight':_sel_parms['imaging_weight']})), "######### ERROR: sel_parms checking failed" # assert(_check_existence_sel_parms(img_dataset,{'pb':_sel_parms['pb'],'weight_pb':_sel_parms['weight_pb']})), "######### ERROR: sel_parms checking failed" # Creating gridding kernel #cgk, correcting_cgk_image = _create_prolate_spheroidal_kernel(_grid_parms['oversampling'], _grid_parms['support'], _grid_parms['imsize_padded']) #cgk_1D = _create_prolate_spheroidal_kernel_1D(_grid_parms['oversampling'], _grid_parms['support']) #Standard Gridd add switch #cgk, correcting_cgk_image = _create_prolate_spheroidal_kernel(100, 7, _grid_parms['imsize_padded']) #cgk_1D = _create_prolate_spheroidal_kernel_1D(100, 7) #grids_and_sum_weights = _graph_standard_grid(vis_dataset, cgk_1D, _grid_parms) _grid_parms['grid_weights'] = False _grid_parms['do_psf'] = False _grid_parms['oversampling'] = np.array(gcf_dataset.oversampling) grids_and_sum_weights = _graph_aperture_grid(_vis_dataset,gcf_dataset,_grid_parms,_vis_sel_parms) uncorrected_dirty_image = dafft.fftshift(dafft.ifft2(dafft.ifftshift(grids_and_sum_weights[0], axes=(0, 1)), axes=(0, 1)), axes=(0, 1)) #Remove Padding print('grid sizes',_grid_parms['image_size_padded'][0], _grid_parms['image_size_padded'][1]) uncorrected_dirty_image = _remove_padding(uncorrected_dirty_image,_grid_parms['image_size']).real * (_grid_parms['image_size_padded'][0] * _grid_parms['image_size_padded'][1]) #print(_img_sel_parms) normalized_image = _normalize(uncorrected_dirty_image, grids_and_sum_weights[1], img_dataset, gcf_dataset, 'forward', _norm_parms, _img_sel_parms) if _grid_parms['chan_mode'] == 'continuum': freq_coords = [da.mean(_vis_dataset.coords['chan'].values)] chan_width = da.from_array([da.mean(_vis_dataset['chan_width'].data)],chunks=(1,)) imag_chan_chunk_size = 1 elif _grid_parms['chan_mode'] == 'cube': freq_coords = _vis_dataset.coords['chan'].values chan_width = _vis_dataset['chan_width'].data imag_chan_chunk_size = _vis_dataset.DATA.chunks[2][0] ###Create Image Dataset chunks = _vis_dataset.DATA.chunks n_imag_pol = chunks[3][0] #coords = {'d0': np.arange(_grid_parms['image_size'][0]), 'd1': np.arange(_grid_parms['image_size'][1]), # 'chan': freq_coords, 'pol': np.arange(n_imag_pol), 'chan_width' : ('chan',chan_width)} #img_dataset = img_dataset.assign_coords(coords) #img_dataset[_sel_parms['sum_weight']] = xr.DataArray(grids_and_sum_weights[1], dims=['chan','pol']) #img_dataset[_sel_parms['image']] = xr.DataArray(normalized_image, dims=['d0', 'd1', 'chan', 'pol']) phase_center = _grid_parms['phase_center'] image_size = _grid_parms['image_size'] cell_size = _grid_parms['cell_size'] phase_center = _grid_parms['phase_center'] pol_coords = _vis_dataset.pol.data time_coords = [_vis_dataset.time.mean().data] _img_dataset = make_empty_sky_image(_img_dataset,phase_center,image_size,cell_size,freq_coords,chan_width,pol_coords,time_coords) _img_dataset[_img_sel_parms['data_group_out']['sum_weight']] = xr.DataArray(grids_and_sum_weights[1][None,:,:], dims=['time','chan','pol']) _img_dataset[_img_sel_parms['data_group_out']['image']] = xr.DataArray(normalized_image[:,:,None,:,:], dims=['l', 'm', 'time', 'chan', 'pol']) _img_dataset.attrs['data_groups'][0] = {**_img_dataset.attrs['data_groups'][0],**{_img_sel_parms['data_group_out']['id']:_img_sel_parms['data_group_out']}} #list_xarray_data_variables = [img_dataset[_sel_parms['image']],img_dataset[_sel_parms['sum_weight']]] #return _store(img_dataset,list_xarray_data_variables,_storage_parms) print('######################### Created graph for make_mosaic_with_gcf #########################') return _img_dataset ''' ###Create Dataset chunks = _vis_dataset.DATA.chunks n_imag_pol = chunks[3][0] image_dict = {} coords = {'d0': np.arange(_grid_parms['image_size'][0]), 'd1': np.arange(_grid_parms['image_size'][1]), 'chan': freq_coords, 'pol': np.arange(n_imag_pol), 'chan_width' : ('chan',chan_width)} image_dict[_sel_parms['sum_weight']] = xr.DataArray(grids_and_sum_weights[1], dims=['chan','pol']) image_dict[_sel_parms['image']] = xr.DataArray(normalized_image, dims=['d0', 'd1', 'chan', 'pol']) image_dataset = xr.Dataset(image_dict, coords=coords) list_xarray_data_variables = [image_dataset[_sel_parms['image']],image_dataset[_sel_parms['sum_weight']]] return _store(image_dataset,list_xarray_data_variables,_storage_parms) '''