karabo.imaging.imager_rascil

Overview

This package summarizes legacy tools and functions for the RASCIL imager. RASCIL imaging remains available during the transitional release, but it is deprecated. New workflows should prefer the common backend interface with get_imager(ImagingBackend.SDP) or get_imager(ImagingBackend.WSCLEAN).

Warning

RASCIL support is deprecated and will be removed in a future release. Prefer SDP for Karabo-native imaging, or WSClean when you need WSClean imaging through the common backend interface.

Classes

class RascilDirtyImagerConfig(imaging_npixel: int, imaging_cellsize: float, combine_across_frequencies: bool = True, override_cellsize: bool = False)

Config / parameters of a RascilDirtyImager.

Adds parameters specific to RascilDirtyImager.

imaging_npixel

see DirtyImagerConfig

Type:: int

imaging_cellsize

see DirtyImagerConfig

Type:: float

combine_across_frequencies

see DirtyImagerConfig

Type:: bool

override_cellsize

Override the cellsize if it is above the critical cellsize. Defaults to False.

Type:: bool

__init__(imaging_npixel: int, imaging_cellsize: float, combine_across_frequencies: bool = True, override_cellsize: bool = False) → None

class RascilDirtyImager(config: RascilDirtyImagerConfig)

Dirty imager based on the RASCIL library.

config

Config containing parameters for RASCIL dirty imaging.

Type:: RascilDirtyImagerConfig

__init__(config: RascilDirtyImagerConfig) → None

Initializes the instance with a config.

Parameters:: config (RascilDirtyImagerConfig) – see config attribute

create_dirty_image(visibility: Visibility, /, *, output_fits_path: Path | str | None = None) → Image

Creates a dirty image from a visibility.

Parameters:

visibility – Visibility object from which to create the dirty image. Contains the visibilities of an observation.
output_fits_path – Path to write the dirty image to. Example: /tmp/dirty.fits. If None, will be set to a temporary directory and a default file name. Defaults to None.

Returns:

Dirty image

Return type:

Image

class RascilImageCleanerConfig(imaging_npixel: int, imaging_cellsize: float, ingest_dd: ~typing.List[int] = <factory>, ingest_vis_nchan: int | None = None, ingest_chan_per_vis: int = 1, imaging_nchan: int = 1, imaging_w_stacking: bool | str = True, imaging_flat_sky: bool | str = False, override_cellsize: bool = False, imaging_uvmax: float | None = None, imaging_uvmin: float = 0, imaging_dft_kernel: ~typing.Literal['cpu_looped', 'gpu_raw'] | None = None, client: ~distributed.client.Client | None = None, use_dask: bool = False, n_threads: int = 1, use_cuda: bool = False, img_context: ~typing.Literal['awprojection', '2d', 'ng', 'wg'] = 'ng', clean_algorithm: ~typing.Literal['hogbom', 'msclean', 'mmclean'] = 'hogbom', clean_beam: ~typing.Dict[~typing.Literal['bmaj', 'bmin', 'bpa'], float] | None = None, clean_scales: ~typing.List[int] = <factory>, clean_nmoment: int = 4, clean_nmajor: int = 5, clean_niter: int = 1000, clean_psf_support: int = 256, clean_gain: float = 0.1, clean_threshold: float = 0.0001, clean_component_threshold: float | None = None, clean_component_method: ~typing.Literal['fit', 'extract'] = 'fit', clean_fractional_threshold: float = 0.3, clean_facets: int = 1, clean_overlap: int = 32, clean_taper: ~typing.Literal['none', 'linear', 'tukey'] = 'tukey', clean_restore_facets: int = 1, clean_restore_overlap: int = 32, clean_restore_taper: ~typing.Literal['none', 'linear', 'tukey'] = 'tukey', clean_restored_output: ~typing.Literal['taylor', 'list', 'integrated'] = 'list')

Config / parameters of a RascilImageCleaner.

Adds parameters specific to RascilImageCleaner.

ingest_dd

Data descriptors in MS to read (all must have the same number of channels). Defaults to [0].

Type:: List[int]

ingest_vis_nchan

Number of channels in a single data descriptor in the MS. Defaults to None.

Type:: Optional[int]

ingest_chan_per_vis

Number of channels per blockvis (before any average). Defaults to 1.

Type:: int

imaging_nchan

Number of channels per image. Defaults to 1.

Type:: int

imaging_w_stacking

Use the improved w stacking method in Nifty Gridder?. Defaults to True.

Type:: Union[bool, str]

imaging_flat_sky

If using a primary beam, normalise to

Type:: Union[bool, str]

flat sky? Defaults to False.

override_cellsize

Override the cellsize if it is above the critical cellsize? Defaults to False.

Type:: bool

imaging_uvmax

TODO. Defaults to None.

Type:: Optional[float]

imaging_uvmin

TODO. Defaults to 0.

Type:: float

imaging_dft_kernel

DFT kernel: cpu_looped | gpu_raw. Defaults to None.

Type:: Optional[DftKernelType]

client

Dask client. Defaults to None.

Type:: Optional[Client]

use_dask

Use dask? Defaults to False.

Type:: bool

n_threads

n_threads per worker. Defaults to 1.

Type:: int

use_cuda

Use CUDA for Nifty Gridder? Defaults to False.

Type:: bool

img_context

Which nifty gridder to use. Defaults to “ng”.

Type:: ImageContextType

clean_algorithm

Deconvolution algorithm (hogbom or msclean or mmclean). Defaults to “hogbom”.

Type:: CleanAlgorithmType

clean_beam

major axis, minor axis, position angle (deg). Defaults to None.

Type:: Optional[Dict[CleanBeamInDegType, float]]

clean_scales

Scales for multiscale clean (pixels) e.g. [0, 6, 10]. Defaults to [0].

Type:: List[int]

clean_nmoment

Number of frequency moments in mmclean (1=constant, 2=linear). Defaults to 4.

Type:: int

clean_nmajor

Number of major cycles in cip or ical. Defaults to 5.

Type:: int

clean_niter

Number of minor cycles in CLEAN. Defaults to 1000.

Type:: int

clean_psf_support

Half-width of psf used in cleaning (pixels). Defaults to 256.

Type:: int

clean_gain

Clean loop gain. Defaults to 0.1.

Type:: float

clean_threshold

Clean stopping threshold (Jy/beam). Defaults to 1e-4.

Type:: float

clean_component_threshold

Sources with absolute flux > this level (Jy) are fit or extracted using skycomponents. Defaults to None.

Type:: Optional[float]

clean_component_method

Method to convert sources in image to skycomponents: “fit” in frequency or “extract” actual values. Defaults to “fit”.

Type:: CleanComponentMethodType

clean_fractional_threshold

Fractional stopping threshold for major cycle. Defaults to 0.3.

Type:: float

clean_facets

axis. Defaults to 1.

Type:: int

clean_overlap

Overlap of facets in clean (pixels). Defaults to 32.

Type:: int

clean_taper

Type of interpolation between facets in deconvolution: none or linear or tukey. Defaults to “tukey”.

Type:: CleanTaperType

clean_restore_facets

Number of overlapping facets in restore step along each axis. Defaults to 1.

Type:: int

clean_restore_overlap

Overlap of facets in restore step (pixels). Defaults to 32.

Type:: int

clean_restore_taper

Type of interpolation between facets in restore step (none, linear or tukey). Defaults to “tukey”.

Type:: CleanTaperType

clean_restored_output

Type of restored image output: taylor, list, or integrated. Defaults to “list”.

Type:: CleanRestoredOutputType

__init__(imaging_npixel: int, imaging_cellsize: float, ingest_dd: ~typing.List[int] = <factory>, ingest_vis_nchan: int | None = None, ingest_chan_per_vis: int = 1, imaging_nchan: int = 1, imaging_w_stacking: bool | str = True, imaging_flat_sky: bool | str = False, override_cellsize: bool = False, imaging_uvmax: float | None = None, imaging_uvmin: float = 0, imaging_dft_kernel: ~typing.Literal['cpu_looped', 'gpu_raw'] | None = None, client: ~distributed.client.Client | None = None, use_dask: bool = False, n_threads: int = 1, use_cuda: bool = False, img_context: ~typing.Literal['awprojection', '2d', 'ng', 'wg'] = 'ng', clean_algorithm: ~typing.Literal['hogbom', 'msclean', 'mmclean'] = 'hogbom', clean_beam: ~typing.Dict[~typing.Literal['bmaj', 'bmin', 'bpa'], float] | None = None, clean_scales: ~typing.List[int] = <factory>, clean_nmoment: int = 4, clean_nmajor: int = 5, clean_niter: int = 1000, clean_psf_support: int = 256, clean_gain: float = 0.1, clean_threshold: float = 0.0001, clean_component_threshold: float | None = None, clean_component_method: ~typing.Literal['fit', 'extract'] = 'fit', clean_fractional_threshold: float = 0.3, clean_facets: int = 1, clean_overlap: int = 32, clean_taper: ~typing.Literal['none', 'linear', 'tukey'] = 'tukey', clean_restore_facets: int = 1, clean_restore_overlap: int = 32, clean_restore_taper: ~typing.Literal['none', 'linear', 'tukey'] = 'tukey', clean_restored_output: ~typing.Literal['taylor', 'list', 'integrated'] = 'list') → None

class RascilImageCleaner(config: RascilImageCleanerConfig)

Image cleaner based on the RASCIL library.

config

Config containing parameters for RASCIL image cleaning.

Type:: RascilImageCleanerConfig

__init__(config: RascilImageCleanerConfig) → None

Initializes the instance with a config.

Parameters:: config (RascilImageCleanerConfig) – see config attribute

create_cleaned_image(visibility: Visibility, /, *, dirty_fits_path: Path | str | None = None, output_fits_path: Path | str | None = None) → Image

Creates a clean image from a dirty image or from visibilities.

Parameters:

visibility – Visibility from which a clean image should be created.
dirty_fits_path – Path to dirty image FITS file that should be reused to create a clean image. If None, dirty image will be created first from the visibilities. Defaults to None.
output_fits_path – Path to write the clean image to. Example: /tmp/restored.fits. If None, will be set to a temporary directory and a default file name. Defaults to None.

Returns:

Clean image

Return type:

Image

create_cleaned_image_variants(visibility: Visibility, /, deconvolved_fits_path: Path | str | None = None, restored_fits_path: Path | str | None = None, residual_fits_path: Path | str | None = None) → Tuple[Image, Image, Image]

Creates a clean image from visibilities.

Parameters:

visibility – Visibility from which a clean image should be created. Please note: only MS visibilities supported.
deconvolved_fits_path – Path to write the deconvolved image to. Example: /tmp/deconvolved.fits. If None, will be set to a temporary directory and a default file name.
restored_fits_path – Path to write the restored image to. Example: /tmp/restored.fits. If None, will be set to a temporary directory and a default file name.
residual_fits_path – Path to write the residual image to. Example: /tmp/residual.fits. If None, will be set to a temporary directory and a default file name.

Returns:

A tuple (deconvolved, restored, residual) of images