nirs4all-datasets

A citable, reproducible bank of raw NIRS (Near-Infrared Spectroscopy) reference datasets — for benchmarking, exploring, and comparing models on a common, version-pinned, provenance-rich footing.

Part of the open-source NIRS tools ecosystem: file readers, datasets, methods, browser modelling, reproducible pipelines, papers, benchmarks, and release dashboards for near-infrared spectroscopy.

A dataset here is raw measured reality, not a benchmark task: one or more spectral sources (instruments), any number of variables (every target and metadata column — nothing is invented, and nothing is thrown away), the native splits if the source defined them, and full provenance back to the origin that published the data. The task — which Y, which split, which metric — is a choice the consumer makes; it is never baked into the dataset.

This repository is split into one native acquisition layer and optional consumer-facing layers:

1. a git-tracked catalog — one hand-checkable descriptor + a machine-generated identity card (stats, per-source/per-variable dataviz, MLCommons Croissant, a Datasheet) per dataset. The heavy bytes never enter git.
2. a native acquisition core — Rust crates + stable n4ds_ C ABI + CLI/bindings that resolve dataset ids, fetch canonical bytes from their origin, verify SHA-256, and manage the platform cache. This surface does not require Python.
3. an optional Python package/binding — nirs4all-datasets embeds that acquisition core for get()/retrieve()/NirsDataset, plus the catalog, cards, and site tooling.
4. optional ecosystem bridges — the [nirs4all] extra for modelling/qualification and the [io] extra for raw-origin reproduction through nirs4all-io / nirs4all-formats.

It reuses nirs4all only through the optional [nirs4all] bridge for qualification and to_nirs4all(), and nirs4all-io / nirs4all-formats only through the optional [io] bridge for raw-origin reproduction. It never re-implements NIRS/IO logic.

Status: 0.3.x, pre-1.0 — the on-disk and API contracts may still change.

The dataset model

• Sources (X) — 1..n, kept separate. Multi-instrument / multi-block datasets keep each block as its own source. Sources may even carry different numbers of spectra (asymmetric repetitions): they are aligned by sample identity (sample_id), never by row position.
• Variables (Y + metadata) — 0..n. There is no intrinsic Y/metadata distinction: every column is a potential target. A dataset may declare no target at all (X-only / metadata-only is valid). Declared targets are flagged; everything else is kept as metadata, with full per-variable dataviz either way.
• Splits — documented, never auto-applied. Native train/test/fold partitions are recorded so you can reproduce a paper's split, but get() never silently applies one.
• Tiers — how a dataset is shown and exported. public (everything shown, openly fetchable from the origin), private (everything shown; export needs a token), anonymized (variable names masked + targets normalized; export needs a token). Bytes are never served from git or the site — the catalog points at the origin DOI/URL; a personal Dataverse is only a future fallback for protected datasets.
• Versions — two axes. A content version (bumps when the dataset bytes change) and a metric-protocol version (lets the cards be re-qualified under a new protocol without rebuilding the data).

Install (development)

uv venv && uv pip install -e ".[dev]"   # builds the optional Python package + embedded native core
# (uses local editable sibling bridges via [tool.uv.sources]; needs a Rust toolchain)

Native acquisition core, bindings, and optional bridges

The download/acquisition path of a dataset — version-pinned DOI resolution, redirect-safe Dataverse / Zenodo / figshare fetch, streaming SHA-256 verification, and platform-cache management — lives in a small Rust core (crates/nirs4all-datasets-core) behind a stable C ABI (n4ds_). The scientific analysis layer (cards, qualify, site, health) stays in Python. The cross-language contract is one distributable catalog/index.json; n4ds resolve returns both the byte contract and the tier-sanitized schema-2.0 descriptor (sources, variables, ids, splits, retrieval). The n4ds CLI is the parity oracle. Surfaces over that core:

Binding	Package	Status
Python	optional nirs4all-datasets package, embedding nirs4all_datasets._n4ds (pyo3)	built + tested
Rust	nirs4all-datasets-core / -capi (crates.io)	built + tested
WASM/JS	@nirs4all/datasets-wasm (npm) — metadata + small public datasets	built + tested
R	nirs4alldatasets (C shim, r-universe / Release)	built + tested
Octave/MATLAB	MEX (GitHub Release zip)	built + tested

See bindings/SPEC.md (the binding contract) and docs/dev/release_process.md.

For the high-level Python API, get()/list()/card() still operate against a registry root checkout (catalog/ + datasets/). For non-Python consumers, the native acquisition core consumes the bundled or committed catalog/index.json contract directly. R/WASM/Rust clients do not need the Python provider package: they resolve the index, inspect the returned descriptor, fetch/verify the listed files, then read the canonical Parquet with host-native tooling.

Quickstart

import nirs4all_datasets as n4ad

n4ad.list()                              # the catalog index
n4ad.card("corn_eigenvector_nir")        # the identity card (dict): sources, variables, stats, provenance

ds = n4ad.get("corn_eigenvector_nir")    # -> NirsDataset (fetched from origin, checksum-verified, cached)
ds.sources()                             # ['X1', 'X2', 'X3'] — the same corn measured on three NIR instruments
ds.x("X1")                               # one source's spectra as a 2D numpy array
ds.x(concat=False)                       # {source_id: array} for every source (sample-aligned, not row-aligned)
ds.y()                                   # all declared targets, per sample
ds.metadata()                            # the metadata columns (each a potential target)
ds.split("original")                     # the native split labels, if the source defined one
ds.to_nirs4all()                         # hand off to nirs4all for modelling

Private / anonymized datasets need a Dataverse token: n4ad.get("name", token=...).

CLI (n4a-datasets)

bootstrap <tree>                 author schema-2.0 descriptors from <tree>/v2.0/*  (--prune to re-base)
build-all --source-tree <tree>   organize + qualify every dataset in parallel  (--protocol-refresh, --site)
add <raw_source> <id>            one raw source -> canonical + card + index
qualify <id>                     (re)build a dataset's card  (--anonymize -> card.anon.json)
health-check                     probe each dataset's open origins -> catalog/health.json
catalog | list | card | get      regenerate the index / inspect / load a dataset
publish | grant | revoke | restrict   personal-Dataverse governance for protected data (future)

n4a-datasets <command> --help documents every flag.

What lives where (3-tier storage)

• git (small, tracked): catalog/datasets/<id>.yaml (descriptor), catalog/datasets.yaml (index + whole-bank summary), and per-dataset card.json / card.md / croissant.json / manifest.json.
• the origin (Zenodo, a data Dataverse, a vendor archive, …): the raw + canonical bytes, fetched on demand and never re-hosted by this project.
• local cache (downloaded on demand): the verified canonical Parquet under the native acquisition core's platform cache root.

API token — where to put it

A Dataverse API token is only needed to fetch private/anonymized datasets or to publish to a personal Dataverse; public datasets need none. Resolution order:

1. Environment variable NIRS4ALL_DATAVERSE_TOKEN (recommended; required in CI).
2. ~/.config/nirs4all-datasets/config.toml (chmod 600):

   [dataverse]
   instance = "https://entrepot.recherche.data.gouv.fr"
   token = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
   

3. A project .env (gitignored) — see .env.example.

The token travels only in the X-Dataverse-key header, is never logged, and is never sent on a redirect to signed object storage. Never commit it (.env, config.toml, *.token are gitignored).

Contributing

Full walkthrough in CONTRIBUTING.md; the design is in docs/DESIGN.md. The green gate (run before every commit) mirrors CI:

ruff check . && mypy --config-file pyproject.toml src
python catalog/scripts/validate.py            # every descriptor is schema-valid
pytest -q

License

Code is dual-licensed open-source — CeCILL-2.1 OR AGPL-3.0-or-later (your choice) — with an optional commercial license for closed-source / SaaS use; for any commercial use, contact nirs4all-admin@cirad.fr. See LICENSING.md, LICENSES/ and THIRD_PARTY_NOTICES.md.

Catalog content (cards, datasheets, metadata) is licensed CC-BY-4.0. Each dataset carries its own SPDX license in its descriptor and is only ever linked to its origin — open data is never re-hosted under a different license.