FringeTask¶
- class lsst.ip.isr.FringeTask(config: Config | None = None, *, name: str | None = None, parentTask: Task | None = None, log: logging.Logger | lsst.utils.logging.LsstLogAdapter | None = None)¶
Bases:
Task
Task to remove fringes from a science exposure
We measure fringe amplitudes at random positions on the science exposure and at the same positions on the (potentially multiple) fringe frames and solve for the scales simultaneously.
Methods Summary
checkFilter
(exposure)Check whether we should fringe-subtract the science exposure.
Empty (clear) the metadata for this Task and all sub-Tasks.
generatePositions
(exposure, rng)Generate a random distribution of positions for measuring fringe amplitudes.
Get metadata for all tasks.
Get the task name as a hierarchical name including parent task names.
getName
()Get the name of the task.
Get a dictionary of all tasks as a shallow copy.
loadFringes
(fringeExp[, expId, assembler])Pack the fringe data into a Struct.
makeField
(doc)Make a
lsst.pex.config.ConfigurableField
for this task.makeSubtask
(name, **keyArgs)Create a subtask as a new instance as the
name
attribute of this task.measureExposure
(exposure, positions[, title])Measure fringe amplitudes for an exposure
removePedestal
(fringe)Remove pedestal from fringe exposure.
run
(exposure, fringes[, seed])Remove fringes from the provided science exposure.
solve
(science, fringes)Solve for the scale factors with iterative clipping.
subtract
(science, fringes, solution)Subtract the fringes.
timer
(name[, logLevel])Context manager to log performance data for an arbitrary block of code.
Methods Documentation
- checkFilter(exposure)¶
Check whether we should fringe-subtract the science exposure.
- Parameters:
- exposure
lsst.afw.image.Exposure
Exposure to check the filter of.
- exposure
- Returns:
- needsFringe
bool
If True, then the exposure has a filter listed in the configuration, and should have the fringe applied.
- needsFringe
- generatePositions(exposure, rng)¶
Generate a random distribution of positions for measuring fringe amplitudes.
- Parameters:
- exposure
lsst.afw.image.Exposure
Exposure to measure the positions on.
- rng
numpy.random.RandomState
Random number generator to use.
- exposure
- Returns:
- positions
numpy.array
Two-dimensional array containing the positions to sample for fringe amplitudes.
- positions
- getFullMetadata() TaskMetadata ¶
Get metadata for all tasks.
- Returns:
- metadata
TaskMetadata
The keys are the full task name. Values are metadata for the top-level task and all subtasks, sub-subtasks, etc.
- metadata
Notes
The returned metadata includes timing information (if
@timer.timeMethod
is used) and any metadata set by the task. The name of each item consists of the full task name with.
replaced by:
, followed by.
and the name of the item, e.g.:topLevelTaskName:subtaskName:subsubtaskName.itemName
using
:
in the full task name disambiguates the rare situation that a task has a subtask and a metadata item with the same name.
- getFullName() str ¶
Get the task name as a hierarchical name including parent task names.
- Returns:
- fullName
str
The full name consists of the name of the parent task and each subtask separated by periods. For example:
The full name of top-level task “top” is simply “top”.
The full name of subtask “sub” of top-level task “top” is “top.sub”.
The full name of subtask “sub2” of subtask “sub” of top-level task “top” is “top.sub.sub2”.
- fullName
- getName() str ¶
Get the name of the task.
- Returns:
- taskName
str
Name of the task.
- taskName
See also
getFullName
Get the full name of the task.
- getTaskDict() dict[str, weakref.ReferenceType[lsst.pipe.base.task.Task]] ¶
Get a dictionary of all tasks as a shallow copy.
- Returns:
- taskDict
dict
Dictionary containing full task name: task object for the top-level task and all subtasks, sub-subtasks, etc.
- taskDict
- loadFringes(fringeExp, expId=None, assembler=None)¶
Pack the fringe data into a Struct.
This method moves the struct parsing code into a butler generation agnostic handler.
- Parameters:
- fringeExp
lsst.afw.exposure.Exposure
The exposure containing the fringe data.
- expId
int
, optional Exposure id to be fringe corrected, used to set RNG seed.
- assembler
lsst.ip.isr.AssembleCcdTask
, optional An instance of AssembleCcdTask (for assembling fringe frames).
- fringeExp
- Returns:
- classmethod makeField(doc: str) ConfigurableField ¶
Make a
lsst.pex.config.ConfigurableField
for this task.- Parameters:
- doc
str
Help text for the field.
- doc
- Returns:
- configurableField
lsst.pex.config.ConfigurableField
A
ConfigurableField
for this task.
- configurableField
Examples
Provides a convenient way to specify this task is a subtask of another task.
Here is an example of use:
class OtherTaskConfig(lsst.pex.config.Config): aSubtask = ATaskClass.makeField("brief description of task")
- makeSubtask(name: str, **keyArgs: Any) None ¶
Create a subtask as a new instance as the
name
attribute of this task.- Parameters:
- name
str
Brief name of the subtask.
- **keyArgs
Extra keyword arguments used to construct the task. The following arguments are automatically provided and cannot be overridden:
config
.parentTask
.
- name
Notes
The subtask must be defined by
Task.config.name
, an instance ofConfigurableField
orRegistryField
.
- measureExposure(exposure, positions, title='Fringe')¶
Measure fringe amplitudes for an exposure
The fringe amplitudes are measured as the statistic within a square aperture. The statistic within a larger aperture are subtracted so as to remove the background.
- Parameters:
- exposure
lsst.afw.image.Exposure
Exposure to measure the positions on.
- positions
numpy.array
Two-dimensional array containing the positions to sample for fringe amplitudes.
- title
str
, optional Title used for debug out plots.
- exposure
- Returns:
- fringes
numpy.array
Array of measured exposure values at each of the positions supplied.
- fringes
- removePedestal(fringe)¶
Remove pedestal from fringe exposure.
- Parameters:
- fringe
lsst.afw.image.Exposure
Fringe data to subtract the pedestal value from.
- fringe
- run(exposure, fringes, seed=None)¶
Remove fringes from the provided science exposure.
Primary method of FringeTask. Fringes are only subtracted if the science exposure has a filter listed in the configuration.
- Parameters:
- Returns:
- solution
np.array
Fringe solution amplitudes for each input fringe frame.
- rms
float
RMS error for the fit solution for this exposure.
- solution
- solve(science, fringes)¶
Solve for the scale factors with iterative clipping.
- Parameters:
- science
numpy.array
Array of measured science image values at each of the positions supplied.
- fringes
numpy.array
Array of measured fringe values at each of the positions supplied.
- science
- Returns:
- solution
np.array
Fringe solution amplitudes for each input fringe frame.
- rms
float
RMS error for the fit solution for this exposure.
- solution
- subtract(science, fringes, solution)¶
Subtract the fringes.
- Parameters:
- science
lsst.afw.image.Exposure
Science exposure from which to remove fringes.
- fringes
lsst.afw.image.Exposure
orlist
thereof Calibration fringe files containing master fringe frames.
- solution
np.array
Fringe solution amplitudes for each input fringe frame.
- science
- Raises:
- RuntimeError
Raised if the number of fringe frames does not match the number of measured amplitudes.