Source code for ngcasa.imaging.make_psf

#  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.
#
#  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
"""

#Removed for now.
#grid_parms['oversampling'] : int, default = 100
#    The oversampling used for the convolutional gridding kernel. This will be removed in a later release and incorporated in the function that creates gridding convolutional kernels.
#grid_parms['support'] : int, default = 7
#    The full support used for convolutional gridding kernel. This will be removed in a later release and incorporated in the function that creates gridding convolutional kernels.
#

[docs]def make_psf(vis_mxds, img_xds, grid_parms, vis_sel_parms, img_sel_parms): """ Creates a cube or continuum point spread function (psf) image from the user specified uvw and imaging weight data. Only the prolate spheroidal convolutional gridding function is supported (this will change in a future releases.) Parameters ---------- vis_mxds : xarray.core.dataset.Dataset Input multi-xarray Dataset with global data. img_xds : 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. vis_sel_parms : dictionary vis_sel_parms['xds'] : str The xds within the mxds to use to calculate the imaging weights for. vis_sel_parms['data_group_in_id'] : int, default = first id in xds.data_groups The data group in the xds to use. img_sel_parms : dictionary img_sel_parms['data_group_in_id'] : int, default = first id in xds.data_groups The data group in the image xds to use. img_sel_parms['psf'] : str, default ='PSF' The created image name. img_sel_parms['psf_sum_weight'] : str, default ='PSF_SUM_WEIGHT' The created sum of weights name. Returns ------- img_xds : xarray.core.dataset.Dataset The image_dataset will contain the image created and the sum of weights. """ print('######################### Start make_psf #########################') 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 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 cngi.image import make_empty_sky_image from cngi.image import fit_gaussian #print('****',sel_parms,'****') _mxds = vis_mxds.copy(deep=True) _img_xds = img_xds.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) ##############Parameter Checking and Set Defaults############## assert(_check_grid_parms(_grid_parms)), "######### ERROR: grid_parms checking failed" 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_xds = _mxds.attrs[_vis_sel_parms['xds']] #Check vis data_group _check_sel_parms(_vis_xds,_vis_sel_parms) #Check img data_group _check_sel_parms(_img_xds,_img_sel_parms,new_or_modified_data_variables={'sum_weight':'PSF_SUM_WEIGHT','psf':'PSF','psf_fit':'PSF_FIT'},append_to_in_id=True) ################################################################################## # Creating gridding kernel _grid_parms['oversampling'] = 100 _grid_parms['support'] = 7 cgk, correcting_cgk_image = _create_prolate_spheroidal_kernel(_grid_parms['oversampling'], _grid_parms['support'], _grid_parms['image_size_padded']) cgk_1D = _create_prolate_spheroidal_kernel_1D(_grid_parms['oversampling'], _grid_parms['support']) _grid_parms['complex_grid'] = False _grid_parms['do_psf'] = True _grid_parms['do_imaging_weight'] = False grids_and_sum_weights = _graph_standard_grid(_vis_xds, cgk_1D, _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 correcting_cgk_image = _remove_padding(correcting_cgk_image,_grid_parms['image_size']) 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]) #############Normalize############# def correct_image(uncorrected_dirty_image, sum_weights, correcting_cgk): sum_weights_copy = copy.deepcopy(sum_weights) ##Don't mutate inputs, therefore do deep copy (https://docs.dask.org/en/latest/delayed-best-practices.html). sum_weights_copy[sum_weights_copy == 0] = 1 # corrected_image = (uncorrected_dirty_image/sum_weights[:,:,None,None])/correcting_cgk[None,None,:,:] corrected_image = (uncorrected_dirty_image / sum_weights_copy) / correcting_cgk return corrected_image corrected_dirty_image = da.map_blocks(correct_image, uncorrected_dirty_image, grids_and_sum_weights[1][None, None, :, :],correcting_cgk_image[:, :, None, None]) #################################################### if _grid_parms['chan_mode'] == 'continuum': freq_coords = [da.mean(_vis_xds.coords['chan'].values)] chan_width = da.from_array([da.mean(_vis_xds['chan_width'].data)],chunks=(1,)) imag_chan_chunk_size = 1 elif _grid_parms['chan_mode'] == 'cube': freq_coords = _vis_xds.coords['chan'].values chan_width = _vis_xds['chan_width'].data imag_chan_chunk_size = _vis_xds.DATA.chunks[2][0] 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_xds.pol.data time_coords = [_vis_xds.time.mean().data] _img_xds = make_empty_sky_image(_img_xds,phase_center,image_size,cell_size,freq_coords,chan_width,pol_coords,time_coords) _img_xds[_img_sel_parms['data_group_out']['sum_weight']] = xr.DataArray(grids_and_sum_weights[1][None,:,:], dims=['time','chan','pol']) _img_xds[_img_sel_parms['data_group_out']['psf']] = xr.DataArray(corrected_dirty_image[:,:,None,:,:], dims=['l', 'm', 'time', 'chan', 'pol']) _img_xds.attrs['data_groups'][0] = {**_img_xds.attrs['data_groups'][0],**{_img_sel_parms['data_group_out']['id']:_img_sel_parms['data_group_out']}} _img_xds = fit_gaussian(_img_xds,dv=_img_sel_parms['data_group_out']['psf'],beam_set_name=_img_sel_parms['data_group_out']['psf_fit']) print('######################### Created graph for make_psf #########################') return _img_xds ''' 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 ngcasa._ngcasa_utils._store import _store from ngcasa._ngcasa_utils._check_parms import _check_storage_parms, _check_sel_parms, _check_existence_sel_parms from ._imaging_utils._check_imaging_parms import _check_grid_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 _grid_parms = copy.deepcopy(grid_parms) _storage_parms = copy.deepcopy(storage_parms) _sel_parms = copy.deepcopy(sel_parms) assert(_check_sel_parms(_sel_parms,{'uvw':'UVW','imaging_weight':'IMAGING_WEIGHT','sum_weight':'SUM_WEIGHT_PSF','image':'PSF'})), "######### ERROR: sel_parms checking failed" assert(_check_existence_sel_parms(vis_dataset,{'uvw':_sel_parms['uvw'],'imaging_weight':_sel_parms['imaging_weight']})), "######### ERROR: sel_parms checking failed" assert(_check_grid_parms(_grid_parms)), "######### ERROR: grid_parms checking failed" assert(_check_storage_parms(_storage_parms,'psf.img.zarr','make_psf')), "######### ERROR: storage_parms checking failed" # Creating gridding kernel _grid_parms['oversampling'] = 100 _grid_parms['support'] = 7 cgk, correcting_cgk_image = _create_prolate_spheroidal_kernel(_grid_parms['oversampling'], _grid_parms['support'], _grid_parms['image_size_padded']) cgk_1D = _create_prolate_spheroidal_kernel_1D(_grid_parms['oversampling'], _grid_parms['support']) _grid_parms['complex_grid'] = False _grid_parms['do_psf'] = True grids_and_sum_weights = _graph_standard_grid(vis_dataset, cgk_1D, _grid_parms, _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 correcting_cgk_image = _remove_padding(correcting_cgk_image,_grid_parms['image_size']) 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]) #############Normalize############# def correct_image(uncorrected_dirty_image, sum_weights, correcting_cgk): sum_weights_copy = copy.deepcopy(sum_weights) ##Don't mutate inputs, therefore do deep copy (https://docs.dask.org/en/latest/delayed-best-practices.html). sum_weights_copy[sum_weights_copy == 0] = 1 # corrected_image = (uncorrected_dirty_image/sum_weights[:,:,None,None])/correcting_cgk[None,None,:,:] corrected_image = (uncorrected_dirty_image / sum_weights_copy) / correcting_cgk return corrected_image corrected_dirty_image = da.map_blocks(correct_image, uncorrected_dirty_image, grids_and_sum_weights[1][None, None, :, :],correcting_cgk_image[:, :, None, None]) #################################################### 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(corrected_dirty_image, dims=['d0', 'd1', 'chan', 'pol']) 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) '''