IsrStatisticsTask

class lsst.ip.isr.IsrStatisticsTask(statControl=None, **kwargs)

Bases: lsst.pipe.base.Task

Task to measure arbitrary statistics on ISR processed exposures.

The goal is to wrap a number of optional measurements that are useful for calibration production and detector stability.

Methods Summary

emptyMetadata()	Empty (clear) the metadata for this Task and all sub-Tasks.
getFullMetadata()	Get metadata for all tasks.
getFullName()	Get the task name as a hierarchical name including parent task names.
getName()	Get the name of the task.
getTaskDict()	Get a dictionary of all tasks as a shallow copy.
makeField(doc)	Make a lsst.pex.config.ConfigurableField for this task.
makeKernel(kernelSize)	Make a boxcar smoothing kernel.
makeSubtask(name, **keyArgs)	Create a subtask as a new instance as the name attribute of this task.
measureBanding(inputExp, overscans)	Task to measure banding statistics.
measureCti(inputExp, overscans, gains)	Task to measure CTI statistics.
measureProjectionStatistics(inputExp, overscans)	Task to measure metrics from image slicing.
run(inputExp[, ptc, overscanResults])	Task to run arbitrary statistics.
timer(name, logLevel)	Context manager to log performance data for an arbitrary block of code.

Methods Documentation

emptyMetadata() → None

Empty (clear) the metadata for this Task and all sub-Tasks.

getFullMetadata() → lsst.pipe.base._task_metadata.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.

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”.

getName() → str

Get the name of the task.

Returns:

taskName : str

Name of the task.

See also

getFullName

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.

classmethod makeField(doc: str) → lsst.pex.config.configurableField.ConfigurableField

Make a lsst.pex.config.ConfigurableField for this task.

Parameters:

doc : str

Help text for the field.

Returns:

configurableField : lsst.pex.config.ConfigurableField

A ConfigurableField for this task.

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")

static makeKernel(kernelSize)

Make a boxcar smoothing kernel.

Parameters:

kernelSize : int

Size of the kernel in pixels.

Returns:

kernel : np.array

Kernel for boxcar smoothing.

makeSubtask(name: str, **keyArgs) → 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”.

Notes

The subtask must be defined by Task.config.name, an instance of ConfigurableField or RegistryField.

measureBanding(inputExp, overscans)

Task to measure banding statistics.

Parameters:

inputExp : lsst.afw.image.Exposure

Exposure to measure.

overscans : list [lsst.pipe.base.Struct]

List of overscan results. Expected fields are:

imageFit

Value or fit subtracted from the amplifier image data (scalar or lsst.afw.image.Image).

overscanFit

Value or fit subtracted from the overscan image data (scalar or lsst.afw.image.Image).

overscanImage

Image of the overscan region with the overscan correction applied (lsst.afw.image.Image). This quantity is used to estimate the amplifier read noise empirically.

Returns:

outputStats : dict [str, [dict [str,`float]]

Dictionary of measurements, keyed by amplifier name and statistics segment.

measureCti(inputExp, overscans, gains)

Task to measure CTI statistics.

Parameters:

inputExp : lsst.afw.image.Exposure

Exposure to measure.

overscans : list [lsst.pipe.base.Struct]

List of overscan results. Expected fields are:

imageFit

Value or fit subtracted from the amplifier image data (scalar or lsst.afw.image.Image).

overscanFit

Value or fit subtracted from the overscan image data (scalar or lsst.afw.image.Image).

overscanImage

Image of the overscan region with the overscan correction applied (lsst.afw.image.Image). This quantity is used to estimate the amplifier read noise empirically.

gains : dict [str float]

Dictionary of per-amplifier gains, indexed by amplifier name.

Returns:

outputStats : dict [str, [dict [str,`float]]

Dictionary of measurements, keyed by amplifier name and statistics segment.

measureProjectionStatistics(inputExp, overscans)

Task to measure metrics from image slicing.

Parameters:

inputExp : lsst.afw.image.Exposure

Exposure to measure.

overscans : list [lsst.pipe.base.Struct]

List of overscan results. Expected fields are:

imageFit

Value or fit subtracted from the amplifier image data (scalar or lsst.afw.image.Image).

overscanFit

Value or fit subtracted from the overscan image data (scalar or lsst.afw.image.Image).

overscanImage

Image of the overscan region with the overscan correction applied (lsst.afw.image.Image). This quantity is used to estimate the amplifier read noise empirically.

Returns:

outputStats : dict [str, [dict [str,`float]]

Dictionary of measurements, keyed by amplifier name and statistics segment.

run(inputExp, ptc=None, overscanResults=None, **kwargs)

Task to run arbitrary statistics.

The statistics should be measured by individual methods, and add to the dictionary in the return struct.

Parameters:

inputExp : lsst.afw.image.Exposure

The exposure to measure.

ptc : lsst.ip.isr.PtcDataset, optional

A PTC object containing gains to use.

overscanResults : list [lsst.pipe.base.Struct], optional

List of overscan results. Expected fields are:

imageFit

Value or fit subtracted from the amplifier image data (scalar or lsst.afw.image.Image).

overscanFit

Value or fit subtracted from the overscan image data (scalar or lsst.afw.image.Image).

overscanImage

Image of the overscan region with the overscan correction applied (lsst.afw.image.Image). This quantity is used to estimate the amplifier read noise empirically.

Returns:

resultStruct : lsst.pipe.base.Struct

Contains the measured statistics as a dict stored in a field named results.

Raises:

RuntimeError

Raised if the amplifier gains could not be found.

timer(name: str, logLevel: int = 10) → Iterator[None]

Context manager to log performance data for an arbitrary block of code.

Parameters:

name : str

Name of code being timed; data will be logged using item name: Start and End.

logLevel

A logging level constant.

See also

timer.logInfo

Examples

Creating a timer context:

with self.timer("someCodeToTime"):
    pass  # code to time