Input Parameters

This page details the various inputs expected by CrossMatch via its input parameter files. These are split into two main sections: inputs that both catalogues need separately (contained in their respective catalogue parameters file) and inputs that are defined with respect to the catalogue-catalogue cross-match.

These input parameters are required to be in a file for the Joint Parameters options, and two further, separate files for the Catalogue-specific Parameters options.

Depending on the size of the match being performed, it is likely that you may want to use the MPI parallelisation option to save runtime or memory overhead, splitting your matches into “chunks.” Even if your cross-match area is small enough that you only have a single file per catalogue, this is treated as a single chunk. Most cross-match parameters are common across all chunks – such as the input photometric magnitude columns, or whether certain match algorithm components are turned on or not – but some are unique to each chunk. Certain parameters will be constant but vary with the chunk ID, and will require a _{} within their input parameter, such that Python’s .format functionality will insert the designation. Others will be totally static, while any input keywords ending in _per_chunk, as well as specifically the chunk_id_list will be a multi-line YAML entry, one line per chunk (such that the first line of chunk_id_list matches the first line of each per-chunk entry, and so on).

For a simple example of how this works for a one-chunk cross-match, see Quick Start, and for more details on the inputs and outputs from individual functions within the cross-match process check the documentation.

CrossMatch Inputs

As well as the parameters required that are ingested through the input parameters files, CrossMatch itself requires some input arguments.

• crossmatch_params_file_path, cat_a_params_file_path, and cat_b_params_file_path: the file paths to the three input metadata files containing parameters files

• use_mpi: boolean flag for whether to parallelise distribution of chunks using MPI. If False chunks will be run in serial; defaults to True, but with a fallback for if the appropriate module is not available.

If you do not want to (or cannot) use MPI to distribute larger cross-match runs, with numerous chunks that will take significant compute time to run, then the first two inputs, combined with with use_mpi=False, are all you need to consider. However, if you wish to use MPI then the remaining keyword arguments control its use:

• resume_file_path: location of where to store the file that contains information on whether a particular chunk (e.g. 2018 in the example above) is finished, to avoid re-running parameters if matches have to be re-started for any reason. Optional, defaulting to having no such checkpointing capabilities.

• walltime: related to resume_file_path, this controls how long a singular run of the cross-matching can be performed for on the particular machine before being stopped (e.g. if being run on a shared machine). Default is no such consideration for duration of match runtimes, but otherwise expects a string in the format H:M:S.

• end_within: combined with walltime this avoids unnecessarily starting new chunks being run by the MPI manager if within end_within of the walltime stoppage. Also expects H:M:S string format.

• polling_rate: controls the speed at which the MPI manager checks for finished jobs and distributes follow-up jobs to the worker.

Joint Parameters

These parameters are only provided in the single, common-parameter input file, and given as joint_file_path in CrossMatch.

There are some parameters that must be given in all runs:

output_save_folder, include_perturb_auf, include_phot_like, use_phot_priors, pos_corr_dist, cf_region_type, cf_region_frame, cf_region_points_per_chunk, chunk_id_list, real_hankel_points, four_hankel_points, four_max_rho, int_fracs, make_output_csv, and n_pool;

options which need to be supplied if make_output_csv is True:

match_out_csv_name, and nonmatch_out_csv_name;

options that must be supplied if include_phot_like is True:

with_and_without_photometry;

those options which only need to be supplied if include_perturb_auf is True:

num_trials, and d_mag;

Note

num_trials and d_mag currently need to be supplied if either correct_astrometry option in the two Catalogue-specific Parameters config files is True as well.

and those options which need to be supplied if either of apply_proper_motion or ref_apply_proper_motion is True, in either catalogue:

move_to_epoch or move_to_epoch_per_chunk.

Common Parameter Description

output_save_folder

The folder path into which to save the stored .csv files that are created if make_output_csv is True, or .npy files are saved otherwise.

include_perturb_auf

Flag for whether to include the simulated effects of blended sources on the measured astrometry in the two catalogues or not.

Note

If include_perturb_auf is True then dustmaps will be called to obtain line-of-sight extinction values. You will need the SFD dustmaps to be pre-downloaded; to do so before you call the cross-match procedure you must run dustmaps.sfd.fetch(); see the dustmaps documentation for more details on how to specific a particular download location.

include_phot_like

Flag for the inclusion of the likelihood of match or non-match based on the photometric information in the two catalogues.

use_phot_priors

Flag to determine whether to calculate the priors on match or non-match using the photometry (if set to True) or calculate them based on a naive asymmetric density argument (False).

pos_corr_dist

The floating point precision number determining the maximum possible separation between two sources in opposing catalogues.

cf_region_type

This flag controls whether the areas in which photometry-related variables (likelihoods, priors, etc.) are calculated is determined by rectangle – evenly spaced longitude/latitude pairings – or points – tuples of randomly placed coordinates.

cf_region_frame

This allows either equatorial or galactic frame coordinates to be used in the match process.

cf_region_points_per_chunk

The list of pointings for which to run simulations of perturbations due to blended sources, if applicable. If cf_region_type is rectangle, then cf_region_points accepts six numbers: start longitude, end longitude, number of longitude points, start latitude, end latitude, number of latitude points; if points then tuples must be of the syntax [[a, b], [c, d]] where a and c are RA or Galactic Longitude, and b and d are Declination or Galactic Latitude. Each chunk must have an element of these pointing lists; these can be produced on a single line, or make use of YAML multi-line formatting to more easily visualise the list-of-point-values, which will produce a list of length N, of which each element will either be a length-six list or an Mx2 nested list.

Note

cf_region_points longitudes may be given with negative coordinates for cases where the match area is both above and below zero degrees, but they can also be given within the [0, 360] phase space, as 350 degrees and -10 degrees are handled the same where needed by cf_region_points.

chunk_id_list

A single entry per chunk, to have the same length as cf_region_points_per_chunk, of unique IDs for each chunk. This is the list of chunks to run cross-matches for, and must be contained within the lists of chunks given in the chunk_id_list entries of each input catalogue. However – for example, when an all-sky catalogue matches with a non-all-sky dataset – the joint-parameter list of chunk IDs can be smaller in number, and a subset of those given in the catalogue-specific parameter files.

real_hankel_points

The integer number of points, for Hankel (two-dimensional Fourier) transformations, in which to approximate the fourier transformation integral of the AUFs.

four_hankel_points

The integer number of points for approximating the inverse Hankel transformation, representing the convolution of two real-space AUFs.

four_max_rho

The largest fourier-space value, up to which inverse Hankel transformation integrals are considered. Should typically be larger than the inverse of the smallest typical centroiding Gaussian one-dimensional uncertainty.

n_pool

Determines how many CPUs are used when parallelising within Python using multiprocessing.

int_fracs

The integral fractions of the various so-called “error circles” used in the cross-match process. Should be list of floats, in the order of: bright error circle fraction, “field” error circle fraction, and potential counterpart cutoff limit. Note that bright and “field” fractions should be reasonably separated in value (more than maybe 0.1) to avoid biasing results that use both to measure photometry-based priors, when applicable.

match_out_csv_name

Name of the band-merged, cross-matched dataset of counterpart associations and accompanying metadata, including the appropriate file extension. Must be a single string containing _{}, into which the chunk ID is inserted.

nonmatch_out_csv_name

Filename to save out the respective non-match catalogue objects and metadata to. Will have appended to the front cat_name to distinguish the two non-match files. nonmatch_out_csv_name should contain the appropriate file extension. Must be a single string containing _{}, into which the chunk ID is inserted.

with_and_without_photometry

Boolean flag that should be given if include_phot_like is True, to indicate whether to run an astrometry-only cross-match in addition to a full astrometry-plus-photometry match. In this case, a second counterpart determination is called with photometric likelihoods ignored, and a second set of counterparts, match probabilities, etc. is recorded.

num_trials

The number of PSF realisations to draw when simulating the perturbation component of the AUF. Should be an integer. Only required if include_perturb_auf is True.

d_mag

Bin sizes for magnitudes used to represent the source number density used in the random drawing of perturbation AUF component PSFs. Should be a single float. Only required if include_perturb_auf is True.

move_to_epoch

The epoch to which proper motions should be fast-forwarded or re-wound, in either catalogue (and astrometric correction reference catalogues, as appropriate). Should be a single string formatted in such a way that it can be read by astropy’s Time function, such as J2000 or 2000-01-01. If move_to_epoch_per_chunk is given this should not be supplied.

move_to_epoch_per_chunk

A per-chunk version of move_to_epoch, Time-valid strings for each parallelised match separately. Only one of the two entries should be given in the joint config file.

Catalogue-specific Parameters

These parameters are required in two separate files, one per catalogue to be cross-matched, the files cat_a_params.txt and cat_b_params.txt read from sub-folders within chunks_folder_path as passed to CrossMatch.

These can be divided into those inputs that are always required:

cat_csv_file_path, cat_name, pos_and_err_indices, mag_indices, chunk_overlap_col, best_mag_index_col, csv_has_header, filt_names, auf_file_path, auf_region_type, auf_region_frame, auf_region_points_per_chunk, chunk_id_list, apply_proper_motion, and correct_astrometry;

those that are only required if the Joint Parameters option include_perturb_auf is True:

fit_gal_flag, run_fw_auf, run_psf_auf, psf_fwhms, download_tri, tri_set_name, tri_filt_names, tri_filt_num, tri_maglim_faint, tri_num_faint, gal_al_avs, dens_dist, snr_indices, tri_dens_cube_location, and tri_dens_array_location;

the inputs required in each catalogue parameters file if fit_gal_flag is True (and hence include_perturb_auf is True):

gal_wavs, gal_zmax, gal_nzs, gal_aboffsets, and gal_filternames;

inputs required if make_output_csv is True:

input_csv_file_path, cat_col_names, cat_col_nums, extra_col_names, and extra_col_nums;

the inputs required if correct_astrometry is True:

correct_astro_save_folder, correct_astro_mag_indices_index, nn_radius, ref_cat_csv_file_path, correct_mag_array, correct_mag_slice, correct_sig_slice, use_photometric_uncertainties, saturation_magnitudes, and ref_apply_proper_motion;

Note

run_fw_auf, run_psf_auf, psf_fwhms, download_tri, tri_set_name, tri_filt_names, tri_filt_num, tri_maglim_faint, tri_num_faint, dens_dist, gal_wavs, gal_zmax, gal_nzs, gal_aboffsets, gal_filternames, gal_al_avs, and snr_indices are all currently required if correct_astrometry is True, bypassing the nested flags above. For example, dens_dist is required as an input if include_perturb_auf is True, or if correct_astrometry is set. This means that AstrometricCorrections implicitly always runs and fits for a full Astrometric Uncertainty Function.

the inputs required if apply_proper_motion is True:

pm_indices, and ref_epoch_or_index;

and the inputs required if ref_apply_proper_motion is True (and hence correct_astrometry is also True):

ref_pm_indices, and ref_ref_epoch_or_index.

Catalogue Parameter Description

cat_csv_file_path

The filepath to the .csv file of the input catalogue (see Quick Start for more details). Can either be an absolute path, or relative to the folder from which the script was called, including the _{} chunk ID flag requirement.

cat_name

The name of the catalogue. This is used to generate intermediate folder structure within the cross-matching process, and during any output file creation process.

pos_and_err_indices

A list of either three, six, or N integers. If correct_astrometry is True, a list of either six or N integers. If use_photometric_uncertainties is False then the first three elements are the zero-indexed indices into the input catalogue .csv file (cat_csv_file_path) for the longitudinal coordinate, latitudinal coordinate, and circular astrometric precision respectively, followed by the lon/lat/uncert of the reference catalogue (ref_cat_csv_file_path). For example, [10, 9, 8, 0, 1, 2] suggests that the reference catalogue begins with the position and uncertainty of its objects while the catalogue “a” or “b” sources have, in their original .csv file, a backwards list of coordinates and precisions towards the final columns of the filing system. If photometric uncertainties are to be used to correct astrometric uncertainties, then the first two elements should be input longitude and latitude, followed by all indices for the input catalogue’s photometric uncertainty columns, with the three reference catalogue longitude, latitude, and circular astrometric precision columns. Otherwise for correct_astrometry being False then only three integers should be passed, the respective coordinates for its own catalogue (dropping the indices of the reference catalogue and requiring that astrometric uncertainty be the third index); in the above example we would therefore only pass [10, 9, 8].

mag_indices

Just for the input catalogue, a list of len(filt_names) integers detailing the zero-indexed column number of the magnitudes in the dataset.

chunk_overlap_col

Column number in the original csv file for the column containing the boolean flag indicating whether sources are in the “halo” or “core” of the chunk. Used within CrossMatch after calling AstrometricCorrections to create final npy arrays via csv_to_npy. Should be a single integer number.

best_mag_index_col

The zero-indexed integer column number in the original input csv file used in AstrometricCorrections that corresponds to the column containing the highest quality detection for each source in the catalogue, used in csv_to_npy.

csv_has_header

A boolean, yes/no, for whether there is a header in the first line of the .csv input catalogue files (True), or if the first line is a line of data (False).

filt_names

The filter names of the photometric bandpasses used in this catalogue, in the order in which they are saved in con_cat_photo. These will be used to describe any output data files generated after the matching process. Should be a list.

auf_file_path

The folder and file name into which the Astrometric Uncertainty Function (AUF) related files will be, or have been, saved. Can also either be an absolute or relative path, like cat_csv_file_path. Alternatively, this can (and must) be None if all parameters related to loading pre-computed TRILEGAL histograms (tri_dens_cube_location) are provided. Requires _{} in the string for chunking purposes.

auf_region_type

Similar to cf_region_type, flag indicating which definition to use for determining the pointings of the AUF simulations; accepts either rectangle or points. If rectangle, then auf_region_points will map out a rectangle of evenly spaced points, otherwise it accepts pairs of coordinates at otherwise random coordinates.

auf_region_frame

As with auf_region_frame, this flag indicates which frame the data, and thus AUF simulations, are in. Can either be equatorial or galactic, allowing for data to be input either in Right Ascension and Declination, or Galactic Longitude and Galactic Latitude.

auf_region_points_per_chunk

Based on auf_region_type, this must either by list of six floats, controlling the start and end, and number of, longitude and latitude points in start lon end lon # steps start lat end lat #steps order (see cf_region_points), or a nested list of lists cf. [[a, b], [c, d]]. Similar to cf_region_points_per_chunk, must be a value per chunk ID of chunk_id_list in the specific catalogue parameter file, to be bundled into a list wrapper of length the number of chunks.

Note

auf_region_points longitudes may be given with negative coordinates for cases where the match area is both above and below zero degrees, but they can also be given within the [0, 360] phase space, as 350 degrees and -10 degrees are handled the same where needed by auf_region_points.

chunk_id_list

A single entry per chunk, to have the same length as auf_region_points_per_chunk, of unique IDs for each chunk. Must agree with the list in chunk_id_list in the joint-catalogue parameter file, and be a super-set of those chunks to be matched (i.e., no chunks can be in the joint catalogue match file without being in both catalogue-only input files).

apply_proper_motion

Boolean flag indicating whether, for this catalogue, we should apply known proper motion information to project the particular epoch (see ref_epoch_or_index) to another time (see move_to_epoch).

correct_astrometry

In cases where catalogues have unreliable centroid uncertainties, before catalogue matching occurs the dataset can be fit for systematic corrections to its quoted astrometric precisions through ensemble match separation distance distributions to a higher-precision dataset (see the Processing section). This flag controls whether this is performed on a chunk-by-chunk basis during the initialisation step of CrossMatch.

Note

If correct_astrometry is True then dustmaps will be called to obtain line-of-sight extinction values. You will need the SFD dustmaps to be pre-downloaded; to do so before you call the cross-match procedure you must run dustmaps.sfd.fetch(); see the dustmaps documentation for more details on how to specific a particular download location.

fit_gal_flag

Optional flag for whether to include simulated external galaxy counts, or just include Galactic sources when deriving the perturbation component of the AUF. Only needed if include_perturb_auf is True.

run_fw_auf

Boolean flag controlling the option to include the flux-weighted algorithm for determining the centre-of-light perturbation with AUF component simulations. Only required if include_perturb_auf is True.

run_psf_auf

Complementary flag to run_fw_auf, indicates whether to run background-dominated, PSF photometry algorithm for the determination of perturbation due to hidden contaminant objects. If both this and run_fw_auf are True a signal-to-noise-based weighting between the two algorithms is implemented. Must be provided if include_perturb_auf is True.

psf_fwhms

The Full-Width-At-Half-Maximum of each filter’s Point Spread Function (PSF), in the same order as in filt_names. These are used to simulate the PSF if include_perturb_auf is set to True, and are unnecessary otherwise. Should be a list of floats.

download_tri

Boolean flag, indicating whether to re-download a TRILEGAL simulation in a given auf_region_points sky coordinate, once it has successfully been run, and to overwrite the original simulation data or not. Optional if include_perturb_aufs is False. Alternatively, this can (and must) be None if all parameters related to loading pre-computed TRILEGAL histograms (tri_dens_cube_location) are provided.

tri_set_name

The name of the filter set used to simulate the catalogue’s sources in TRILEGAL [1]. Used to interact with the TRILEGAL API; optional if include_perturb_aufs is False. Alternatively, this can (and must) be None if all parameters related to loading pre-computed TRILEGAL histograms (tri_dens_cube_location) are provided.

tri_filt_names

The names of the filters, in the same order as filt_names, as given in the data tri_set_name calls. Optional if include_perturb_aufs is False. Alternatively, this can (and must) be None if all parameters related to loading pre-computed TRILEGAL histograms (tri_dens_cube_location) are provided.

tri_filt_num

The one-indexed column number of the magnitude, as determined by the column order of the saved data returned by the TRILEGAL API, to which to set the maximum magnitude limit for the simulation. Optional if include_perturb_aufs is False. Alternatively, this can (and must) be None if all parameters related to loading pre-computed TRILEGAL histograms (tri_dens_cube_location) are provided.

tri_maglim_faint

This is the float that represents the magnitude down to which to simulate TRILEGAL sources in the full-scale simulation, bearing in mind the limiting magnitude cut of the public API but also making sure this value is sufficiently faint that it contains all potentially perturbing objects for the dynamic range of this catalogue (approximately 10 magnitudes fainter than the limiting magnitude of the survey). Alternatively, this can (and must) be None if all parameters related to loading pre-computed TRILEGAL histograms (tri_dens_cube_location) are provided.

tri_num_faint

Integer number of objects to draw from the TRILEGAL simulation – affecting the area of simulation, up to the limit imposed by TRILEGAL – down to the full tri_maglim_faint magnitude. Alternatively, this can (and must) be None if all parameters related to loading pre-computed TRILEGAL histograms (tri_dens_cube_location) are provided.

tri_dens_cube_location

The location on disk of a numpy array, shape (A, len(filt_names), B, M), of differential source counts, magnitudes bins, and magnitude bin widths for a series TRILEGAL simulations at A number of sky positions, in each filter, for a specific catalogue. Alternatively, should be None if auf_file_path and associated parameters for the running of TRILEGAL histogram generation within the cross-match run are given.

tri_dens_array_location

Location on disk of a numpy array to accompany tri_dens_cube_location, of shape (A, 2), with the corresponding sky coordinates for each simulation.

dens_dist

The radius, in arcseconds, within which to count internal catalogue sources for each object, to calculate the local source density. Used to scale TRILEGAL simulated source counts to match smaller scale density fluctuations. Only required if include_perturb_auf is True.

snr_indices

Similar to mag_indices, a list of len(mag_indices) integers, one for each column in mag_indices for where the corresponding signal-to-noise ratio column is held for each magnitude in the input .csv file.

gal_wavs

List of floating point central wavelengths, in the order filters are given in filt_names, for each filter, in microns. Used to approximate Schechter function parameters for deriving galaxy counts. Must be given if fit_gal_flag is True, and hence only required if include_perturb_auf is True.

gal_zmax

Maximum redshift z to calculate galactic densities out to for Schechter function derivations, one per gal_wavs point. Only needed if fit_gal_flag is True.

gal_nzs

Integer number of redshift points, from zero to gal_zmax, to evaluate Schechter functions on, for each filter. Must be given if fit_gal_flag is True.

gal_aboffsets

For each filter, floating point offset between the given filter’s zeropoint system and that of the AB magnitude system – in the same that m = m_AB - offset_AB – for each filter. If fit_gal_flag is True, must be provided.

gal_filternames

Name of each filter as appropriate for providing to speclite for each filter. See generate_speclite_filters for how to create appropriate filters if not provided by the module by default. Required if fit_gal_flag is True.

gal_al_avs

Differential extinction relative to the V-band for each filter, a list of floats. Must be provided if include_perturb_auf is True.

input_csv_file_path

Full filepath of the catalogue’s original input .csv file, generally converted to a binary file for use within the main code via csv_to_npy, including filename and extension. Should have _{} formatting within the string for chunk-identification purposes.

cat_col_names

The names of the mandatory columns from each respctive catalogue. Should contain at least the column name for the name or ID of the object, and the names of the columns containing the two orthogonal sky coordinates, as well as the names of each column containing magnitude information to be transferred to the output match and non-match files.

cat_col_nums

For each column name in cat_col_names, cat_col_nums is the zero-indexed position of the column. For example, if we had ['ID', 'RA', 'Dec', 'V'] as our cat_col_names, we might have [0, 1, 2, 5] as our cat_col_nums, in which our designation and coordinates are the first three columns, but our V-band magnitude is a few columns down.

extra_col_names

Analogous to cat_col_names, a list of the additional columns from the original csv catalogue file that we wish to add to the match and non-match output files.

extra_col_nums

The zero-indexed positions of each corresponding column in extra_col_names, much the same as in cat_col_nums, but for additional, optional columns we may wish to transfer from input to output dataset.

correct_astro_mag_indices_index

For the purposes of correcting systematic biases in a given catalogue, a single photometric band is used. correct_astro_mag_indices_index indicates which filter to use – e.g., correct_astro_mag_indices_index = 0 says to use the first filter as given in filt_names or mag_indices. Must be a single integer value no larger than len(filt_names)-1.

nn_radius

Nearest neighbour radius out to which to search for potential counterparts for the purposes of ensemble match separation distributions; should be a single float.

correct_astro_save_folder

File path, relative or absolute, into which to save files as generated by the astrometric correction process. Must include _{} to allow for formatting for each chunk separately.

ref_cat_csv_file_path

Similar to cat_csv_file_path, but the path and filename, including extension, of the reference dataset used in the matching process. These chunks should correspond one-to-one with those used in cat_csv_file_path – i.e., data_1.csv in /your/path/to/file should be the same region of the sky as the reference catalogue in /another/path/to/elsewhere/reference_data_1.csv, potentially with some buffer overlap to avoid false matches at the edges. Must include _{} to allow for formatting for each chunk separately.

correct_mag_array

List of magnitude arrays at which to evaluate the distribution of matches to the higher-astrometric-precision dataset in each input-catalogue photometric filter. Accepts a list of lists of floats, or two-dimensional array, with the first axis the same length as mag_indices.

correct_mag_slice

Corresponding to each magnitude in correct_mag_array, each element of this list of lists of floats should be a width around each correct_mag_array element to select sources, ensuring a small sub-set of similar brightness objects are used to determine the Astrometric Uncertainty Function of.

correct_sig_slice

Elementwise with correct_mag_array and correct_mag_slice, a list of lists of floats of widths of astrometric precision to select a robust sub-sample of objects in each magnitude bin for, ensuring a self-similar AUF.

use_photometric_uncertainties

Boolean flag indicating whether the astrometric or photometric uncertainties of the input catalogue should be used to derive the astrometric uncertainties from ensemble statistics in AstrometricCorrections.

saturation_magnitudes

A list, one float per filter, of the magnitudes in the given filter at which the telescope or survey saturates, used in the filtering of source counts for model-fitting purposes in AstrometricCorrections.

pm_indices

List of integers for the two orthogonal sky indices that contain the proper motion information in the catalogue being cross-matched, used to propagate its given epoch to that declared in the joint-match configuration, move_to_epoch.

ref_epoch_or_index

Either a single epoch that all observations are provided at, in which case – similar to move_to_epoch – the string should be formatted such that astropy’s Time function can parse it (e.g. J2000 or 2000-01-01); or an index into the file that contains the epochs of each observation, one per row, to be moved to move_to_epoch on a case-by-case basis.

ref_apply_proper_motion

Boolean flag for whether to apply proper motions to this catalogue’s reference catalogue during astrometric precision parameterisation and characterisation.

ref_pm_indices

A list of integers, the index for the two ortogonal sky proper motion columns in the reference catalogue being loaded during astrometric corrections, similar to pm_indices, if supplied, for the catalogue being parameterised and/or cross-matched.

ref_ref_epoch_or_index

The reference catalogue’s “reference” epoch, used to propagate the reference cataloue to move_to_epoch before this catalogue has its uncertainties parameterised, as necessary. Formats expected are the same as ref_epoch_or_index: single, Time-compatible string, or index into reference catalogue from which an epoch per row can be extracted.

Parameter Dependency Graph

The inter-dependency of input parameters on one another, and the output CrossMatch attribute if different, are given below:

├─> include_perturb_auf
│                     ├─> num_trials
│                     ├─> d_mag
│                     ├─* dens_dist
│                     ├─* fit_gal_flag
│                     │              ├─* gal_wavs
│                     │              ├─* gal_zmax
│                     │              ├─* gal_nzs
│                     │              ├─* gal_aboffsets
│                     │              ├─* gal_filternames
│                     │              └─* saturation_magnitudes
│                     ├─* snr_indices
│                     ├─* tri_set_name[2a]
│                     ├─* tri_filt_names[2a]
│                     ├─* tri_filt_num[2a]
│                     ├─* tri_maglim_faint[2a]
│                     ├─* tri_num_faint[2a]
│                     ├─* download_tri[2a]
│                     ├─* psf_fwhms
│                     ├─* run_fw_auf
│                     ├─* run_psf_auf
│                     ├─* gal_al_avs
│                     ├─* tri_dens_cube_location[2b] => tri_dens_cube
│                     └─* tri_dens_array_location[2b] => tri_dens_array
├─> include_phot_like
│                   └─> with_and_without_photometry
├─> use_phot_priors
├─> cf_region_type
├─> cf_region_frame[1]
├─> cf_region_points_per_chunk[4]
├─> chunk_id_list[4]
├─> output_save_folder
├─> pos_corr_dist
├─> real_hankel_points
├─> four_hankel_points
├─> four_max_rho
├─> int_fracs
├─> make_output_csv
│                 ├─> match_out_csv_name[3]
│                 ├─> nonmatch_out_csv_name[3]
│                 ├─* cat_col_names
│                 ├─* cat_col_nums
│                 ├─* extra_col_names
│                 └─* extra_col_nums
├─> n_pool
├─* auf_region_type
├─* auf_region_frame[1]
├─* auf_region_points_per_chunk[4]
├─* chunk_id_list[4]
├─* filt_names
├─* cat_name
├─* auf_file_path[2a, 3]
├─* cat_csv_file_path[3]
├─* pos_and_err_indices
├─* mag_indices
├─* chunk_overlap_col
├─* best_mag_index_col
├─* csv_has_header
├─* apply_proper_motion
│                     ├─> move_to_epoch[5,6]
│                     ├─> move_to_epoch_per_chunk[5,6]
│                     ├─* pm_indices
│                     └─* ref_epoch_or_index
└─* correct_astrometry
                     ├─* correct_astro_save_folder[3]
                     ├─* snr_indices
                     ├─* ref_apply_proper_motion
                     │                         ├─> move_to_epoch[5,6]
                     │                         ├─> move_to_epoch_per_chunk[5,6]
                     │                         ├─* ref_pm_indices
                     │                         └─* ref_ref_epoch_or_index
                     ├─* correct_astro_mag_indices_index
                     ├─* nn_radius
                     ├─* ref_cat_csv_file_path[3]
                     ├─* correct_mag_array
                     ├─* correct_mag_slice
                     ├─* correct_sig_slice
                     ├─* use_photometric_uncertainties
                     └─* saturation_magnitudes

List directories end in -> for joint parameters, -* for catalogue parameters. catalogue level items will have a_ or b_ prepended, depending on which “side” of the cross-match they are from. Items with a second keyword after an arrow => are the names of the attributes that are saved to CrossMatch, usually when the input parameter is a location on disk.

[1] - must be the same

[2] - only one set of [2a] and [2b] should be given, if one or more from both sets is provided an error will be raised

[3] - must have _{} in its string, into which the chunk ID will be inserted

[4] - must have relevant input entry per chunk, e.g. in a YAML multi-line format, aligned with the chunk ID of chunk_id_list of the relevant input parameter file

[5] - must be provided in either apply_proper_motion or ref_apply_proper_motion are True in either input catalogue

[6] - only one of move_to_epoch or move_to_epoch_per_chunk should be given

Footnotes

[1]

Please see here to view the TRILEGAL papers to cite, if you use this software in your publication.