ExposureSelector

class daschlab.exposures.ExposureSelector(exposures: Exposures, apply)[source]

Bases: object

A helper object that supports Exposures filtering functionality.

Exposure selector objects are returned by exposure selection “action verbs” such as Exposures.keep_only. Calling one of the methods on a selector instance will apply the associated action to the specified portion of the lightcurve data.

See the introduction to the daschlab.lightcurves module for an overview of the filtering framework used here.

Attributes Summary

not_

Get a selector that will act on an inverted row selection.

Methods Summary

has_imaging(**kwargs)

Act on exposures that can be associated to imaging data.

has_phot(**kwargs)

Act on exposures that were able to be photometrically calibrated.

jyear_range(jyear_min, jyear_max, **kwargs)

Act on exposures observed within the specified Julian-year time range.

local_id(local_id, **kwargs)

Act on the row with the specified local ID.

meteor(**kwargs)

Act on rows associated with ultra-low-resolution "meteor" telescopes.

narrow(**kwargs)

Act on rows associated with narrow-field telescopes.

patrol(**kwargs)

Act on rows associated with low-resolution "patrol" telescopes.

plate_names(names, **kwargs)

Act on rows associated with the specified plate names.

rejected(**kwargs)

Act on rows with a non-zero "reject" value.

rejected_with(tag[, strict])

Act on rows that have been rejected with the specified tag.

scanned(**kwargs)

Act on exposures corresponding to plates that have been scanned.

series(series, **kwargs)

Act on rows associated with the specified plate series.

where(row_mask, **kwargs)

Act on exactly the specified list of rows.

Attributes Documentation

not_

Get a selector that will act on an inverted row selection.

Examples

Create an exposure-list subset containing only those exposures that do not have associated imaging data:

from astropy import units as u

exp = sess.exposures()
unsolved = exposures.keep_only.not_.has_imaging()

In general, the function of this modifier is such that:

exp.ACTION.not_.CONDITION() # should be equivalent to:
exp.ACTION.where(~exp.match.CONDITION())

Methods Documentation

has_imaging(**kwargs) → Exposures[source]

Act on exposures that can be associated to imaging data.

Parameters:
**kwargs

Parameters forwarded to the action.

Returns:
Usually, another Exposures

However, different actions may return different types. For instance, the Exposures.count action will return an integer.

Notes

Unfortunately, some of the DASCH WCS solutions are erroneous.

Examples

Create an exposure-list subset containing only exposures with imaging:

exp = sess.exposures()
solved = exp.keep_only.has_imaging()
has_phot(**kwargs) → Exposures[source]

Act on exposures that were able to be photometrically calibrated.

Parameters:
**kwargs

Parameters forwarded to the action.

Returns:
Usually, another Exposures

However, different actions may return different types. For instance, the Exposures.count action will return an integer.

Notes

The selector acts on exposures that have data in the lim_mag_{refcat} field, where {refcat} is the reference catalog being used by this session: either apass or atlas. This field is only present for exposures that have imaging and were successfully processed by the DASCH photometric pipeline for that refcat.

Examples

Count the number of exposures with photometry:

exp = sess.exposures()
n_phot = exp.count.has_phot()
jyear_range(jyear_min: float, jyear_max: float, **kwargs) → Exposures[source]

Act on exposures observed within the specified Julian-year time range.

Parameters:
jyear_minfloat

The lower limit of the time range (inclusive).

jyear_maxfloat

The upper limit of the time range (inclusive).

**kwargs

Parameters forwarded to the action.

Returns:
Usually, another Exposures

However, different actions may return different types. For instance, the Exposures.count action will return an integer.

Notes

The comparison is performed against the jyear attribute of the contents of the "obs_date" column.

Examples

Create an exposure-list subset containing exposures observed in the 1920’s:

exp = sess.exposures()
subset = exp.keep_only.jyear_range(1920, 1930)
local_id(local_id: int, **kwargs) → Exposures[source]

Act on the row with the specified local ID.

Parameters:
local_idint

The local ID to select.

**kwargs

Parameters forwarded to the action.

Returns:
Usually, another Exposures

However, different actions may return different types. For instance, the Exposures.count action will return an integer.

Notes

Exposure local IDs are unique, and so this filter should only ever match at most one row.

Examples

Create an exposure-list subset containing only the chronologically first row:

exp = sess.exposures()
first = exp.keep_only.local_id(0)
meteor(**kwargs) → Exposures[source]

Act on rows associated with ultra-low-resolution “meteor” telescopes.

Parameters:
**kwargs

Parameters forwarded to the action.

Returns:
Usually, another Exposures

However, different actions may return different types. For instance, the Exposures.count action will return an integer.

Examples

Create an exposure-list subset containing only exposures from meteor telescopes:

exp = sess.exposures()
meteor = exp.keep_only.meteor()
narrow(**kwargs) → Exposures[source]

Act on rows associated with narrow-field telescopes.

Parameters:
**kwargs

Parameters forwarded to the action.

Returns:
Usually, another Exposures

However, different actions may return different types. For instance, the Exposures.count action will return an integer.

Examples

Create an exposure-list subset containing only exposures from narrow-field telescopes:

exp = sess.exposures()
narrow = exp.keep_only.narrow()
patrol(**kwargs) → Exposures[source]

Act on rows associated with low-resolution “patrol” telescopes.

Parameters:
**kwargs

Parameters forwarded to the action.

Returns:
Usually, another Exposures

However, different actions may return different types. For instance, the Exposures.count action will return an integer.

Examples

Create an exposure-list subset containing only exposures from patrol telescopes:

exp = sess.exposures()
patrol = exp.keep_only.patrol()
plate_names(names: Iterable[str], **kwargs) → Exposures[source]

Act on rows associated with the specified plate names.

Parameters:
namesiterable of str

Each name should be of the form {series}{platenum}. Capitalization and zero-padding of the plate number are not important.

**kwargs

Parameters forwarded to the action.

Returns:
Usually, another Exposures

However, different actions may return different types. For instance, the Exposures.count action will return an integer.

Examples

Create an exposure-list subset containing exposures on the specified plates:

exp = sess.exposures() subset = exp.keep_only.plate_names([“A10000”, “mc1235”])

rejected(**kwargs) → Exposures[source]

Act on rows with a non-zero "reject" value.

Parameters:
**kwargs

Parameters forwarded to the action.

Returns:
Usually, another Exposures

However, different actions may return different types. For instance, the Exposures.count action will return an integer.

Examples

Create an exposure-list subset containing only rejected rows:

exp = sess.exposures()
rejects = exp.keep_only.rejected()
rejected_with(tag: str, strict: bool = False, **kwargs) → Exposures[source]

Act on rows that have been rejected with the specified tag.

Parameters:
tagstr

The tag used to identify the rejection reason

strictoptional bool, default False

If true, and the specified tag has not been defined, raise an exception. Otherwise, the action will be invoked with no rows selected.

**kwargs

Parameters forwarded to the action.

Returns:
Usually, another Exposures

However, different actions may return different types. For instance, the Exposures.count action will return an integer.

Examples

Create an exposure-list subset containing only rows rejected with the “astrom” tag:

exp = sess.exposures() astrom_rejects = exp.keep_only.rejected_with(“astrom”)

scanned(**kwargs) → Exposures[source]

Act on exposures corresponding to plates that have been scanned.

Parameters:
**kwargs

Parameters forwarded to the action.

Returns:
Usually, another Exposures

However, different actions may return different types. For instance, the Exposures.count action will return an integer.

Notes

Some exposures are known to have occurred, and are associated with plates that have been scanned, but the pipeline was unable to find an associated WCS solution in the plate imagery. Use has_imaging() to act only on exposures with WCS solutions.

Examples

Create an exposure-list subset containing only exposures from unscanned plates:

exp = sess.exposures()
unscanned = exp.drop.scanned()
# or equivalently:
unscanned = exp.keep_only.not_.scanned()
series(series: str, **kwargs) → Exposures[source]

Act on rows associated with the specified plate series.

Parameters:
seriesstr

The plate series to select.

**kwargs

Parameters forwarded to the action.

Returns:
Usually, another Exposures

However, different actions may return different types. For instance, the Exposures.count action will return an integer.

Examples

Create an exposure-list subset containing only exposures from the MC series:

exp = sess.exposures()
mcs = exp.keep_only.series("mc")
where(row_mask, **kwargs) → Exposures[source]

Act on exactly the specified list of rows.

Parameters:
row_maskboolean numpy.ndarray

A boolean array of exactly the size of the input exposure list, with true values indicating rows that should be acted upon.

**kwargs

Parameters forwarded to the action.

Returns:
Usually, another Exposures

However, different actions may return different types. For instance, the Exposures.count action will return an integer.

Examples

Create an exposure-list subset containing only exposures that are from A-series exposures and do not have associated imaging data:

exp = sess.exposures()
subset = exp.keep_only.where(
    exp.match.series("a") & exp.match.not_.has_imaging()
)