use-linear

Install

[dependencies]
use-linear = "0.0.5"
use-matrix = "0.0.5"
use-vector = "0.0.5"

Foundation

use-linear provides a deliberately small linear-algebra surface focused on algorithms that compose the primitive crates. The current slice includes solve_2x2 plus LinearError for explicit handling of singular or non-finite systems. Matrix primitives live in use-matrix, and vector primitives live in use-vector.

Helper group	Primary items	Best fit
Solves and error handling	`solve_2x2`, `LinearError`	Small systems where singular behavior should stay explicit
Neighbor primitives	`use-matrix`, `use-vector`	Call sites that want focused matrix and vector ownership boundaries

When to use directly

Choose use-linear directly when solve-oriented helpers are the only linear surface you need and you want primitive ownership to stay in neighboring crates.

Scenario	Use `use-linear` directly?	Why
You need explicit handling of singular 2×2 solves	Yes	The API keeps solve failures visible through `LinearError`
You want matrix and vector types to stay in focused crates	Yes	`use-linear` composes `use-matrix` and `use-vector` instead of redefining them
You also need geometry, calculus, or other math domains	Usually no	`use-math` can compose the concrete surfaces behind features

Scope

use-matrix owns matrix primitives and direct matrix operations.
use-vector owns vector primitives and vector operations.
use-linear owns higher-level linear algorithms over those primitives.
The crate intentionally does not define its own matrix/vector types, geometry transforms, or decomposition frameworks.

Examples

Solving a 2x2 system

use use_linear::solve_2x2;
use use_matrix::Matrix2;
use use_vector::Vector2;

let matrix = Matrix2::new(2.0, 1.0, 5.0, 3.0);
let rhs = Vector2::new(1.0, 2.0);

assert_eq!(solve_2x2(matrix, rhs)?, Vector2::new(1.0, -1.0));
# Ok::<(), use_linear::LinearError>(())

Handling singular systems

use use_linear::{LinearError, solve_2x2};
use use_matrix::Matrix2;
use use_vector::Vector2;

let matrix = Matrix2::new(1.0, 2.0, 2.0, 4.0);
let rhs = Vector2::new(1.0, 2.0);

assert_eq!(
    solve_2x2(matrix, rhs),
    Err(LinearError::SingularMatrix { determinant: 0.0 })
);

Status

use-linear is a concrete pre-1.0 crate in the RustUse math workspace. The API remains intentionally small while use-matrix and use-vector own the primitive surface and adjacent crates continue to grow around them.

use-linear 0.0.6