euclidkit 0.2.3

Euclid Archival Data Analysis Package

euclidkit

A comprehensive Python package for Euclid archival data analysis, designed for use within the ESA Datalabs environment.

Overview

euclidkit facilitates advanced data exploration and visualization for Euclid Q1/(I)DR1 archival releases, including:

• Data Access: Query and crossmatch sources with the Euclid MER catalogue
• Segmentation Maps: Resolve MER segmentation-map metadata from crossmatch results
• Spectroscopic Analysis: Access, download, and combine NISP spectra of archival sources
• Unified Workflow: Streamlined tools for researchers working with Euclid spectroscopic data

The package is designed for efficient archive querying and Euclid spectrum compilation workflows.

Installation

Requirements

• Python 3.11+
• Access to ESA Datalabs environment (for data volumes)
• COSMOS credentials for Euclid archive access

Basic Installation

pip install euclidkit

Development Installation

git clone https://github.com/rudolffu/euclidkit.git
cd euclidkit
pip install -e .

Quick Start

Setup Credentials

Store credentials in a private file under your home directory and restrict permissions:

mkdir -p ~/.euclidkit
touch ~/.euclidkit/.cred.txt
chmod 600 ~/.euclidkit/.cred.txt

Edit ~/.euclidkit/.cred.txt manually with your preferred editor (do not put credentials in shell history).

Use two lines:

1. COSMOS username
2. COSMOS password

Configuration

Create and edit the user config file:

euclidkit init-config --output ~/.euclidkit/euclidkit_config.yaml --template basic

Then edit ~/.euclidkit/euclidkit_config.yaml and set the credential path.

Set the credential path in the config:

data:
  credentials_file: /home/<user>/.euclidkit/.cred.txt

Basic Usage

# Note: the Python import path is currently still `euclidkit`.
from euclidkit.core.data_access import EuclidArchive

# Initialize archive connection
archive = EuclidArchive(environment='PDR')
archive.login()

# Crossmatch your sources with Euclid MER catalogue
results = archive.crossmatch_sources(
    user_table="my_sources.csv",
    radius=1.0,  # arcseconds
    output_file="crossmatch_results.fits"
)

# Query for available spectra
spectra_table = archive.query_spectra_sources(
    crossmatch_table=results,
    output_file="spectra_sources.fits"
)

# Export local Datalabs spectra rows to Parquet parts
from euclidkit.core.spectra_parquet import spectra_to_parquet

stats = spectra_to_parquet(
    catalog_table="spectra_sources.fits",
    output_prefix="./output/raw_spectra",
    lambda_range="RGS",
)
print(stats.output_files)

Command Line Interface

Crossmatching Sources

# Crossmatch user table with Euclid MER catalogue
euclidkit crossmatch \
    --input my_sources.csv \
    --output crossmatch_results.fits \
    --radius 1.0 \
    --verbose

# Optionally remove columns that are entirely null/missing from the final
# output table. Zero, False, and empty-string columns are retained.
euclidkit crossmatch \
    --input my_sources.csv \
    --output crossmatch_results.fits \
    --drop-empty-columns

# Submit the entire table as a single async job (no batching). The output file
# uses async TAP mode; for very large tables euclidkit splits into async chunks.
euclidkit crossmatch \
    --input my_sources.csv \
    --output crossmatch_results.fits \
    --full-async \
    --async-chunk-size 500000

# When using the IDR environment the command defaults to the WIDE field and
# writes results to wide_<filename>. Use --idr-field DEEP to query DEEP MER.
# DEEP defaults to the deep_survey partition (EDFN, EDFF, EDFS).
euclidkit crossmatch \
    --input my_sources.csv \
    --output crossmatch_results.fits \
    --environment IDR \
    --idr-field DEEP

# Query the deep_mode partition (CDFS, COSMOS), or use "both" for
# deep_survey followed by deep_mode.
euclidkit crossmatch \
    --input my_sources.csv \
    --output crossmatch_results.fits \
    --environment IDR \
    --idr-field DEEP \
    --idr-deep-partition mode

# Crossmatch an already-uploaded archive user table (no local upload needed)
euclidkit crossmatch \
    --user-table-name my_table \
    --output crossmatch_results.fits \
    --match-mode object-id \
    --environment IDR \
    --idr-field WIDE

--full-async behavior:

• For smaller inputs, euclidkit submits one async TAP job, downloads the result to the requested output file, and then removes the remote job.
• For large local input tables (--input), euclidkit splits the upload into async chunks, saves each chunk to <output>_part_####.fits, removes each remote job after the chunk is saved, writes <output>.manifest.json, and merges the chunk files into the requested final output.
• For large archive user tables (--user-table-name), euclidkit uses the same on-disk chunking pattern and final merge.

Matching mode recommendation:

• Prefer --match-mode object-id whenever the input already contains Euclid object_id values, or source_id values that should be joined to MER object_id. This avoids positional matching and is usually faster and more robust for large tables.

--max-sources vs --async-chunk-size:

• --max-sources: limits how many rows from the input table are processed in total.
• --async-chunk-size: controls rows per async TAP job when --full-async is enabled.
• --drop-empty-columns: drops columns where every result value is null or missing before saving the final --output table. Intermediate async part files are left unchanged.

Uploading Tables

# Upload a FITS table to your Euclid TAP workspace
euclidkit upload-table \
    --input my_sources.fits \
    --table-name my_workspace_table \
    --description "Sources awaiting deep crossmatch" \
    --overwrite

# Upload CSV data as-is (format inferred automatically)
euclidkit upload-table \
    --input trimmed_sources.csv \
    --table-name trimmed_sources

Querying Spectra

# Query spectra from crossmatch results
euclidkit query-spectra \
    --crossmatch crossmatch_results.fits \
    --output spectra_sources.fits \
    --environment IDR \
    --idr-field WIDE \
    --verbose

# Query spectra by object IDs and auto-combine
euclidkit query-spectra \
    --object-ids 123456,789012,345678 \
    --output spectra_sources.fits \
    --combine-output my_spectra.fits \
    --max-spectra 100 \
    --verbose

Querying Segmentation Maps

# Resolve segmentation-map files and WCS metadata from MER crossmatch results.
# The input must contain SEGMENTATION_MAP_ID, object_id, and coordinates.
# query-segmap prefers ra/dec and falls back to mer_ra/mer_dec.
euclidkit query-segmap \
    --input crossmatch_results.fits \
    --output segmentation_maps.fits \
    --environment IDR

# Create one raw-label 10 arcsec FITS cutout per source row
euclidkit compile-segmap \
    --input segmentation_maps.fits \
    --output-dir ./segmap_cutouts

query-segmap computes tile_index = floor(SEGMENTATION_MAP_ID / 1_000_000) locally, then joins to q1.mer_segmentation_map for PDR, dr1.mer_segmentation_map for IDR, and sedm.mer_segmentation_map for OTF/REG. Run euclidkit crossmatch first if your table does not yet contain SEGMENTATION_MAP_ID. compile-segmap reads local segmentation-map FITS files from datalabs_path + file_name, groups rows by tile file, and preserves the raw segmentation-label pixels in each cutout. See the segmentation-map guide in the Sphinx docs for required columns, output filenames, and error-handling options.

Building Cutana Input

# Build Cutana CSV from a source table with object_id or ra/dec columns
euclidkit query-cutana \
    --sources my_sources.fits \
    --output cutana_input.csv \
    --instrument VIS \
    --cutout-size arcsec \
    --cutout-size-value 15

# NISP example with explicit filters
euclidkit query-cutana \
    --sources my_sources.fits \
    --output cutana_input_nisp.csv \
    --instrument NISP \
    --nisp-filters NIR_Y,NIR_H \
    --environment IDR \
    --idr-field DEEP \
    --idr-deep-partition both \
    --cutout-size arcsec \
    --cutout-size-value 15

Compiling Spectra

# Default local Datalabs mode: export raw spectra to parquet parts
euclidkit compile-spectra \
    --spectra-table spectra_sources.fits \
    --output-dir ./output \
    --prefix raw_spectra \
    --chunk-size 2000 \
    --workers 8 \
    -L RGS

# Export both arms into separate raw_spectra_rgs / raw_spectra_bgs parquet families
euclidkit compile-spectra \
    --spectra-table spectra_sources.fits \
    --output-dir ./output \
    --prefix raw_spectra \
    -L BOTH

# Legacy local FITS mode remains available explicitly
euclidkit compile-spectra \
    --spectra-table spectra_sources.fits \
    --output-dir ./output \
    --prefix compiled_spectra \
    --output-format fits \
    --max-extensions 1000

# Datalink mode is unchanged and writes FITS outputs
euclidkit compile-spectra \
    --spectra-table spectra_sources.fits \
    --output-dir ./output \
    --prefix compiled_dl \
    --use-datalink \
    --environment IDR \
    --schema sedm \
    -L BOTH

# Export per-dither spectra from local Datalabs FITS files
euclidkit dithers-to-parquet \
    --catalog-table spectra_sources.fits \
    --output-prefix ./output/raw_sir \
    --workers 8 \
    --lambda-range RGS

Note: non-Datalink compile-spectra now defaults to Parquet and reads LRANGE from FITS headers for -L/--lambda-range filtering. Datalink remains FITS-only; RGS/BGS map to corresponding retrieval types, and BOTH runs two passes and writes separate _rgs and _bgs FITS files. --retrieval-type is kept for backward compatibility.

Key Features

Data Archive Integration

• Multiple Environments: Support for PDR, IDR, OTF, and REG archive environments
• Efficient Queries: Batch processing with TAP table uploads for large datasets
• Crossmatching: Position-based matching with configurable search radius

Spectroscopic Tools

• Spectrum Access: Direct access to Euclid data volumes on ESA Datalabs
• Parquet Spectra Export: Export local Datalabs spectra to raw Parquet parts by default
• FITS Compatibility: Keep legacy multi-extension FITS compilation and Datalink FITS outputs available

Analysis Pipeline

• Quality Control: Spectrum validation and quality assessment

Data Environment

ESA Datalabs Integration

This package is optimized for the ESA Datalabs environment with direct access to:

• Euclid Q1 Data: /data/euclid_q1/ (35 TB volume)

API Reference

Core Classes

EuclidArchive

Main interface to the Euclid science archive.

archive = EuclidArchive(environment='PDR')
archive.login(credentials_file='~/.euclidkit/.cred.txt')

# Crossmatch sources
results = archive.crossmatch_sources(
    user_table="sources.csv",
    radius=1.0,
    output_file="results.fits"
)

# Query spectra
spectra = archive.query_spectra_sources(
    crossmatch_table=results,
    output_file="spectra.fits"
)

# Get individual spectrum
spectrum_hdu = archive.get_individual_spectrum(
    datalabs_path="/data/euclid_q1/path",
    file_name="spectrum_file.fits", 
    hdu_index=42
)

# Export queried local Datalabs spectra to raw Parquet parts
from euclidkit.core.spectra_parquet import spectra_to_parquet

stats = spectra_to_parquet(
    catalog_table="spectra.fits",
    output_prefix="./output/raw_spectra",
    chunk_size=2000,
    lambda_range="RGS",
)
print(stats.manifest_path)

Spectra Parquet Export

Default local Datalabs spectra export writes raw Parquet parts directly from catalog rows containing datalabs_path, file_name, hdu_index, source_id, object_id, ra_obj, and dec_obj.

from euclidkit.core.spectra_parquet import spectra_to_parquet, dithers_to_parquet

raw_stats = spectra_to_parquet(
    catalog_table="spectra_sources.fits",
    output_prefix="./output/raw_spectra",
    chunk_size=2000,
    workers=8,
    lambda_range="RGS",
    on_error="skip",
)

dither_stats = dithers_to_parquet(
    catalog_table="spectra_sources.fits",
    output_prefix="./output/raw_sir",
    chunk_size=2000,
    workers=8,
    lambda_range="RGS",
    include_combined=True,
)

SpectrumCompiler remains available for legacy local multi-extension FITS compilation and Datalink FITS outputs.

Workflow Examples

Complete Spectroscopic Analysis Pipeline

from euclidkit.core.data_access import EuclidArchive
from euclidkit.core.spectra_parquet import spectra_to_parquet, dithers_to_parquet
import pandas as pd

# 1. Initialize archive
archive = EuclidArchive(environment='PDR')
archive.login()

# 2. Load your QSO candidates
qso_candidates = pd.read_csv('qso_candidates.csv')

# 3. Crossmatch with Euclid MER catalogue
crossmatches = archive.crossmatch_sources(
    user_table=qso_candidates,
    radius=2.0,  # 2 arcsecond radius
    output_file='qso_crossmatches.fits'
)

# 4. Find available spectra
spectra_sources = archive.query_spectra_sources(
    crossmatch_table=crossmatches,
    output_file='qso_spectra_sources.fits'
)

print(f"Found {len(spectra_sources)} spectra for {len(crossmatches)} crossmatches")

# 5. Export raw spectra to Parquet parts for downstream analysis
raw_stats = spectra_to_parquet(
    catalog_table='qso_spectra_sources.fits',
    output_prefix='./spectra_parquet/qso_raw',
    chunk_size=2000,
    lambda_range='RGS',
    on_error='skip',
)
print(f"Wrote {len(raw_stats.output_files)} raw spectra parquet parts")

# 6. Optionally export per-dither spectra for the same catalog rows
dither_stats = dithers_to_parquet(
    catalog_table='qso_spectra_sources.fits',
    output_prefix='./spectra_parquet/qso_sir',
    lambda_range='RGS',
)
print(f"Wrote {len(dither_stats.dither_output_files)} dither parquet parts")

archive.logout()

Diagnostics

Check your installation and environment:

# Check all components
euclidkit diagnostics

# Check specific components
euclidkit diagnostics --check-deps --check-data

Archive Environments

Use --environment (CLI) or environment=... (Python API) to select the archive backend:

• PDR: Public Data Release archive.
• IDR: Internal Data Release archive (consortium access).
• OTF: On-the-fly archive environment.
• REG: Regression/testing archive environment.

For IDR, you can also select the field with --idr-field:

• WIDE: Uses the IDR WIDE MER catalogue. This queries catalogue.mer_catalogue_wide_survey first, then queries catalogue.mer_catalogue_wide_mode only for sources not matched in the survey table.
• DEEP: Uses IDR DEEP MER partitions. By default this queries catalogue.mer_catalogue_deep_survey (EDFN, EDFF, EDFS). Use --idr-deep-partition mode for catalogue.mer_catalogue_deep_mode (CDFS, COSMOS), or --idr-deep-partition both to query survey first and mode second.

Examples:

# IDR WIDE (default IDR field)
euclidkit crossmatch \
  --input my_sources.fits \
  --output xmatch_wide.fits \
  --environment IDR \
  --idr-field WIDE

# IDR DEEP
euclidkit crossmatch \
  --input my_sources.fits \
  --output xmatch_deep.fits \
  --environment IDR \
  --idr-field DEEP

# IDR DEEP mode partition
euclidkit crossmatch \
  --input my_sources.fits \
  --output xmatch_deep_mode.fits \
  --environment IDR \
  --idr-field DEEP \
  --idr-deep-partition mode

Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

Documentation

For detailed documentation and examples, visit:

• euclidkit docs
• Package Documentation
• Euclid Science Archive
• astroquery.esa.euclid

Support

• Issues: GitHub Issues
• Discussions: GitHub Discussions
• Email: [e-mail]

Author

Yuming Fu (@rudolffu)

• Email: [e-mail]
• GitHub: https://github.com/rudolffu/euclidkit

License

This project is licensed under the BSD 3-Clause License - see the LICENSE file for details.

Acknowledgments

• ESA Euclid Mission and Euclid Consortium
• ESA Datalabs and Euclid Data Space infrastructure team
• Astropy and astroquery communities

Changelog

Latest Changes

• Spectroscopic Pipeline: Complete pipeline for accessing and combining Euclid spectra
• CLI Integration: Added --combine-output option to query-spectra command
• TAP Upload: Improved query performance using TAP table uploads
• Parquet Spectra Export: Default local Datalabs spectra export to Parquet
• Error Handling: Robust handling of long filenames and missing data

See CHANGELOG.md for detailed version history.