solve doesn't return the expected vector

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
rust
Domain
backend

Research direction

Start by reproducing the supplied test_solve case with solve and inspect the implementation and linear-algebra backend it exercises. Compare the returned vector with the stated expected vector and add or update a regression test once the cause is identified; done means solve returns [1.0, 0.0, 1.0, 0.0] for this input.

Written by the indexing model from the issue text.

Description

The following test fails:

#[test]
pub fn test_solve() {
    let a = array![
        [0.2, 0.4, -0.2, -1.0],
        [0.4, 0.8, -0.4, -1.0],
        [0.2, 0.4, 0.0, 0.0],
        [1.0, 1.0, 0.0, 0.0]
    ];
    let b = array![0.0, 0.0, 0.2, 1.0];
    let x = a.solve(&b).unwrap();
    let y = array![1.0, 0.0, 1.0, 0.0];
    assert_eq!(y, x);
}

Instead of [1.0, 0.0, 1.0, 0.0], the solve returns the vector [-2.7333333333333325, 3.7333333333333334, 3.2666666666666657, -5.106666666666666].

This happens on:

os: macos 13.4 (22F66)
processor: 1.2 GHz Quad-Core Intel Core i7
rustc: 1.66.1 (90743e729 2023-01-10)
rust edition: 2021
ndarrary: v0.15.6
ndarray-linalg: v0.16.0
ndarray-linalg features: ["openblas-static"]
Dominant language
Rust
Stars
452
Forks
95
PR merge metrics
No merged PRs in 30d

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