Keyboard shortcuts

Press ← or → to navigate between chapters

Press S or / to search in the book

Press ? to show this help

Press Esc to hide this help

Architecture

matten is a small core crate plus four independent companion crates. The shape is a star, not a stack: every companion depends on core, and core depends on none of them.

graph LR
    ndarray[matten-ndarray] --> core[matten]
    mlprep[matten-mlprep] --> core
    data[matten-data] --> core
    stats[matten-stats] --> core

That shape is enforced from both directions, not just documented:

  • Core depends on no companion. crates/matten/Cargo.toml lists no matten-* dependency, and scripts/check-core-dependency-boundary.sh (RFC-022 §10) fails CI if one is ever added — checked with --all-features, so an optional dependency behind a non-default feature cannot slip past it.
  • No companion depends on another companion (RFC-078 §6). Each crates/matten-*/Cargo.toml lists matten as its only workspace dependency.

This is the fact worth knowing before choosing what to depend on: pick core alone, or core plus exactly the companions you need — never a chain.

The crates

CrateForMaturity
mattenThe Tensor type: construction, shape ops, arithmetic, reductions, the dynamic (Element) on-rampstable (v0.x)
matten-ndarrayConversion bridge to/from ndarray::ArrayD<f64>production-ready
matten-mlprepSmall, transparent preprocessing helpers (scaling, bias columns, splits)production-ready
matten-dataCSV/table ingestion, reaching Tensor via to_tensor()production-ready
matten-statsScalar statistics (covariance, correlation, quantile)production-ready candidate

Core’s Status is README.md’s own label; it sits outside the companion promotion sequence (RFC-057/080/084/085) tracked in detail in Compatibility and stability.

Not part of the published surface

Three local tools and the benchmark harness live in the repository but are workspace-excluded (exclude in the root Cargo.toml) and publish = false: tools/matten-report, tools/matten-migrate, tools/matten-playground, and benchmarks/. None of them ship to crates.io, and none can affect the dependency boundary above — they are excluded from the workspace specifically so their tool-only dependencies never enter it.

Feature matrix

Core’s Cargo feature matrix (default, serde, json, csv, dynamic) is listed once, on the contributor reference page, to avoid two copies drifting apart: see Contributing → Architecture.

Source layout

This page is the reader’s overview. For the module-by-module source layout, public re-exports, and design invariants, see Contributing → Architecture.

The data model

For what a Tensor actually holds, how a value moves from raw input to a computation, and what state a tensor’s storage moves through, see Data model and lifecycle.