FitsRawFormatterBase¶

class lsst.obs.base.FitsRawFormatterBase(*args, **kwargs)¶

Bases: FitsImageFormatterBase

Abstract base class for reading and writing raw data to and from FITS files.

Attributes Summary

`checked_parameters`	The parameters passed by the butler user, after checking them against the storage class and transforming `None` into an empty `dict` (`dict`).
`dataId`	Return Data ID associated with this formatter (`DataCoordinate`).
`extension`
`fileDescriptor`	File descriptor associated with this formatter (`FileDescriptor`).
`filterDefinitions`	`FilterDefinitions`, defining the filters for this instrument.
`metadata`	The metadata read from this file.
`observationInfo`	The `ObservationInfo` extracted from this file's metadata (`ObservationInfo`, read-only).
`supportedExtensions`	Set of all extensions supported by this formatter.
`supportedWriteParameters`	Parameters understood by this formatter that can be used to control how a dataset is serialized.
`translatorClass`	`MetadataTranslator` to translate metadata header to `ObservationInfo`.
`unsupportedParameters`	Support all parameters.
`wcsFlipX`	Control whether the WCS is flipped in the X-direction (`bool`)
`writeParameters`	Parameters to use when writing out datasets.
`writeRecipes`	Detailed write Recipes indexed by recipe name.

Methods Summary

`attachComponentsFromMetadata`(exposure)	Attach all `lsst.afw.image.Exposure` components derived from metadata (including the stripped metadata itself).
`can_read_bytes`()	Indicate if this formatter can format from bytes.
`fromBytes`(serializedDataset[, component])	Read serialized data into a Dataset or its component.
`fromMetadata`(metadata[, obsInfo, ...])	Construct a possibly-limited formatter from known metadata.
`getDetector`(id)	Return the detector that acquired this raw exposure.
`isOnSky`()	Boolean to determine if the exposure is thought to be on the sky.
`makeFilterLabel`()	Construct a FilterLabel from metadata.
`makeRawSkyWcsFromBoresight`(boresight, ...)	Class method to make a raw sky WCS from boresight and detector.
`makeUpdatedLocation`(location)	Return a new `Location` updated with this formatter's extension.
`makeVisitInfo`()	Construct a VisitInfo from metadata.
`makeWcs`(visitInfo, detector)	Create a SkyWcs from information about the exposure.
`name`()	Return the fully qualified name of the formatter.
`predictPath`()	Return the path that would be returned by write.
`read`([component])	Read a Dataset.
`readComponent`(component)	Read a component dataset.
`readFull`()	Read the full dataset (while still accounting for parameters).
`readImage`()	Read just the image component of the Exposure.
`readMetadata`()	Read all header metadata directly into a PropertyList.
`segregateParameters`([parameters])	Segregate the supplied parameters.
`stripMetadata`()	Remove metadata entries that are parsed into components.
`toBytes`(inMemoryDataset)	Serialize the Dataset to bytes based on formatter.
`validateExtension`(location)	Check the extension of the provided location for compatibility.
`validateWriteRecipes`(recipes)	Validate supplied recipes for this formatter.
`write`(inMemoryDataset)	Write a Python object to a file.

Attributes Documentation

checked_parameters¶

dataId¶: Return Data ID associated with this formatter (DataCoordinate).

extension = '.fits'¶

fileDescriptor¶

File descriptor associated with this formatter (FileDescriptor).

Read-only property.

filterDefinitions¶: FilterDefinitions, defining the filters for this instrument.

metadata¶: The metadata read from this file. It will be stripped as components are extracted from it (lsst.daf.base.PropertyList).

observationInfo¶: The ObservationInfo extracted from this file’s metadata (ObservationInfo, read-only).

supportedExtensions: ClassVar[AbstractSet[str]] = frozenset({'.fit', '.fits', '.fits.fz', '.fits.gz', '.fz'})¶

Set of all extensions supported by this formatter.

Only expected to be populated by Formatters that write files. Any extension assigned to the extension property will be automatically included in the list of supported extensions.

supportedWriteParameters: ClassVar[Set[str] | None] = None¶: Parameters understood by this formatter that can be used to control how a dataset is serialized. None indicates that no parameters are supported.

translatorClass¶: MetadataTranslator to translate metadata header to ObservationInfo.

unsupportedParameters: ClassVar[AbstractSet[str]] = frozenset({})¶: Support all parameters.

wcsFlipX = False¶: Control whether the WCS is flipped in the X-direction (bool)

writeParameters¶: Parameters to use when writing out datasets.

writeRecipes¶: Detailed write Recipes indexed by recipe name.

Methods Documentation

attachComponentsFromMetadata(exposure)¶

Attach all lsst.afw.image.Exposure components derived from metadata (including the stripped metadata itself).

Parameters:

exposurelsst.afw.image.Exposure: Exposure to attach components to (modified in place). Must already have a detector attached.

classmethod can_read_bytes() → bool¶

Indicate if this formatter can format from bytes.

Returns:

canbool: True if the fromBytes method is implemented.

fromBytes(serializedDataset: bytes, component: str | None = None) → object¶

Read serialized data into a Dataset or its component.

Parameters:

serializedDatasetbytes: Bytes object to unserialize.
componentstr, optional: Component to read from the Dataset. Only used if the StorageClass for reading differed from the StorageClass used to write the file.

Returns:

inMemoryDatasetobject: The requested data as a Python object. The type of object is controlled by the specific formatter.

classmethod fromMetadata(metadata, obsInfo=None, storageClass=None, location=None)¶

Construct a possibly-limited formatter from known metadata.

Parameters:

metadatalsst.daf.base.PropertyList: Raw header metadata, with any fixes (see astro_metadata_translator.fix_header) applied but nothing stripped.
obsInfoastro_metadata_translator.ObservationInfo, optional: Structured information already extracted from metadata. If not provided, will be read from metadata on first use.
storageClasslsst.daf.butler.StorageClass, optional: StorageClass for this file. If not provided, the formatter will only support makeWcs, makeVisitInfo, makeFilter, and other operations that operate purely on metadata and not the actual file.
locationlsst.daf.butler.Location, optional.: Location of the file. If not provided, the formatter will only support makeWcs, makeVisitInfo, makeFilter, and other operations that operate purely on metadata and not the actual file.

Returns:

formatterFitsRawFormatterBase: An instance of cls.

abstract getDetector(id)¶

Return the detector that acquired this raw exposure.

Parameters:

idint: The identifying number of the detector to get.

Returns:

detectorDetector: The detector associated with that id.

isOnSky()¶

Boolean to determine if the exposure is thought to be on the sky.

Returns:

onSkybool: Returns True if the observation looks like it was taken on the sky. Returns False if this observation looks like a calibration observation.

Notes

If there is tracking RA/Dec information associated with the observation it is assumed that the observation is on sky. Currently the observation type is not checked.

makeFilterLabel()¶

Construct a FilterLabel from metadata.

Returns:

filterFilterLabel: Object that identifies the filter for this image.

classmethod makeRawSkyWcsFromBoresight(boresight, orientation, detector)¶

Class method to make a raw sky WCS from boresight and detector.

Parameters:

boresightlsst.geom.SpherePoint: The ICRS boresight RA/Dec
orientationlsst.geom.Angle: The rotation angle of the focal plane on the sky.
detectorlsst.afw.cameraGeom.Detector: Where to get the camera geomtry from.

Returns:

skyWcsSkyWcs: Reversible mapping from pixel coordinates to sky coordinates.

makeUpdatedLocation(location: Location) → Location¶

Return a new Location updated with this formatter’s extension.

Parameters:

locationLocation: The location to update.

Returns:

updatedLocation: A new Location with a new file extension applied.

Raises:

NotImplementedError: Raised if there is no extension attribute associated with this formatter.

Notes

This method is available to all Formatters but might not be implemented by all formatters. It requires that a formatter set an extension attribute containing the file extension used when writing files. If extension is None the supplied file will not be updated. Not all formatters write files so this is not defined in the base class.

makeVisitInfo()¶

Construct a VisitInfo from metadata.

Returns:

visitInfoVisitInfo: Structured metadata about the observation.

makeWcs(visitInfo, detector)¶

Create a SkyWcs from information about the exposure.

If VisitInfo is not None, use it and the detector to create a SkyWcs, otherwise return the metadata-based SkyWcs (always created, so that the relevant metadata keywords are stripped).

Parameters:

visitInfoVisitInfo: The information about the telescope boresight and camera orientation angle for this exposure.
detectorDetector: The detector used to acquire this exposure.

Returns:

skyWcsSkyWcs: Reversible mapping from pixel coordinates to sky coordinates.

Raises:

InitialSkyWcsError: Raised if there is an error generating the SkyWcs, chained from the lower-level exception if available.

classmethod name() → str¶

Return the fully qualified name of the formatter.

Returns:

namestr: Fully-qualified name of formatter class.

predictPath() → str¶

Return the path that would be returned by write.

Does not write any data file.

Uses the FileDescriptor associated with the instance.

Returns:

pathstr: Path within datastore that would be associated with the location stored in this Formatter.

read(component=None)¶

Read a Dataset.

Parameters:

componentstr, optional: Component to read from the file. Only used if the StorageClass for reading differed from the StorageClass used to write the file.

Returns:

inMemoryDatasetobject: The requested Dataset.

readComponent(component)¶

Read a component dataset.

Parameters:

componentstr, optional: Component to read from the file.

Returns:

objcomponent-dependent: In-memory component object.

Raises:

KeyError: Raised if the requested component cannot be handled.

readFull()¶

Read the full dataset (while still accounting for parameters).

Returns:

objcomponent-dependent: In-memory component object.

readImage()¶

Read just the image component of the Exposure.

Returns:

imageImage: In-memory image component.

readMetadata()¶

Read all header metadata directly into a PropertyList.

Returns:

metadataPropertyList: Header metadata.

segregateParameters(parameters: dict[str, Any] | None = None) → tuple[dict, dict]¶

Segregate the supplied parameters.

This splits the parameters into those understood by the formatter and those not understood by the formatter.

Any unsupported parameters are assumed to be usable by associated assemblers.

Parameters:

parametersdict, optional: Parameters with values that have been supplied by the caller and which might be relevant for the formatter. If None parameters will be read from the registered FileDescriptor.

Returns:

supporteddict: Those parameters supported by this formatter.
unsupporteddict: Those parameters not supported by this formatter.

stripMetadata()¶: Remove metadata entries that are parsed into components.

toBytes(inMemoryDataset: Any) → bytes¶

Serialize the Dataset to bytes based on formatter.

Parameters:

inMemoryDatasetobject: The Python object to serialize.

Returns:

serializedDatasetbytes: Bytes representing the serialized dataset.

classmethod validateExtension(location: Location) → None¶

Check the extension of the provided location for compatibility.

Parameters:

locationLocation: Location from which to extract a file extension.

Raises:

NotImplementedError: Raised if file extensions are a concept not understood by this formatter.
ValueError: Raised if the formatter does not understand this extension.

Notes

This method is available to all Formatters but might not be implemented by all formatters. It requires that a formatter set an extension attribute containing the file extension used when writing files. If extension is None only the set of supported extensions will be examined.

classmethod validateWriteRecipes(recipes: Mapping[str, Any] | None) → Mapping[str, Any] | None¶

Validate supplied recipes for this formatter.

The recipes are supplemented with default values where appropriate.

Parameters:

recipesdict: Recipes to validate.

Returns:

validateddict: Validated recipes.

Raises:

RuntimeError: Raised if validation fails. The default implementation raises if any recipes are given.

write(inMemoryDataset)¶

Write a Python object to a file.

Parameters:

inMemoryDatasetobject: The Python object to store.

Returns:

pathstr: The URI where the primary file is stored.

Navigation

FitsRawFormatterBase¶