matten

A family car of Rust array (tensor) library — easy to start, predictable, and friendly for quick numerical trials / PoCs.

Overview

matten is a developer-experience-first multidimensional array (tensor) library for Rust. It makes early-stage numerical and data-exploration work feel close to NumPy/Pandas ergonomics while staying native Rust: one concrete Tensor type, no visible lifetimes, no generic dtype puzzles, and human-readable failures.

It deliberately favors developer experience over peak performance, and is not a replacement for ndarray, nalgebra, or candle on hot paths.

Why / when to use it

Reach for matten when you want to prototype quickly: represent vectors, matrices, and tensors, do simple shape work and arithmetic, and move messy JSON/CSV in and out — without wrestling with views, lifetimes, or trait bounds. When a prototype becomes performance-critical, matten is designed to hand its flat data off to a specialized crate.

Status: active pre-1.0 development. Phase 1 numeric core is strong; The dynamic feature supports heterogeneous ingestion (from_json_dynamic, from_csv_dynamic), missing-value cleanup (fill_none, none_mask, forward_fill_none), and explicit conversion to numeric tensors (try_numeric). Dynamic reshape, slicing, arithmetic, reductions, and serde are intentionally guarded — call try_numeric() first. Dynamic is a guarded heterogeneous-ingestion and cleanup feature, not a full dynamic tensor arithmetic engine. RFC-000 through RFC-021 are in rfcs/done/. v1.0.0 requires explicit maintainer confirmation. See CHANGELOG.md and docs.rs for details. The full mdBook lives in docs/ in the repository (not included in the crate package).

Quick start

use matten::Tensor;

let a = Tensor::new(vec![1.0, 2.0, 3.0, 4.0], &[2, 2]);
assert_eq!(a.shape(), &[2, 2]);
assert_eq!(a.ndim(), 2);

// Boundary-style construction is recoverable instead of panicking:
use matten::MattenError;
let bad = Tensor::try_new(vec![1.0, 2.0, 3.0], &[2, 2]);
assert!(matches!(bad, Err(MattenError::Shape { .. })));

Lean install (smallest dependency footprint):

matten = { version = "0.19", default-features = false }

Design notes

One primary type. Users work through matten::Tensor. The public root also exposes MattenError and DataFormat; the dynamic Element engine is a Phase 2, feature-gated addition.
Two error zones. Local convenience APIs panic with actionable messages for fast PoC feedback; every external boundary returns Result<_, MattenError> and never panics on ordinary invalid input. MattenError derives only Debug, so match it by variant, not ==.
Convenient by default, lean on request. default = ["serde", "json", "csv"] for a smooth first run; default-features = false for the lean core.
Safe Rust only. The crate is #![forbid(unsafe_code)].

More detail