Crate arpack 

Safe Rust wrapper around ARPACK-NG.

Provides safe drivers for the supported eigenproblem variants (real-symmetric Lanczos and complex Arnoldi). Callers that need to drive ARPACK manually should depend on arpack-sys directly.

Each driver family exposes two layers:

• eigenpairs_* — general entry point that accepts nev >= 1 and a Which selector. Returns a MultiEigSolution.
• smallest_eigenpair_* — convenience wrapper fixed to nev = 1 and the family’s “smallest” mode (Which::SmallestAlgebraic for the real-symmetric driver, Which::SmallestRealPart for the complex Arnoldi driver). Returns a singular EigSolution.

Example

Smallest eigenvalue of diag(1, 2, 3):

use arpack::{Options, smallest_eigenpair_f64};

let diag = [1.0_f64, 2.0, 3.0];
let n = diag.len();

let solution = smallest_eigenpair_f64(
    n,
    |x, y| {
        for i in 0..n {
            y[i] = diag[i] * x[i];
        }
    },
    &Options::default(),
)
.expect("ARPACK converged");

assert!((solution.eigenvalue - 1.0).abs() < 1e-9);

Re-exports

pub use error::Error;

pub use symmetric::Options;

pub use symmetric::eigenpairs_f32;

pub use symmetric::eigenpairs_f64;

pub use symmetric::smallest_eigenpair_f32;

pub use symmetric::smallest_eigenpair_f64;

Modules

arnoldi

Arnoldi-iteration eigenvalue drivers (*naupd_c / *neupd_c).

error

symmetric

Real-symmetric eigenvalue drivers backed by the ARPACK-NG {s,d}{sa,se}upd_c family (Implicitly Restarted Lanczos).

Structs

EigSolution

The eigenpair returned by a driver, plus the diagnostic counters ARPACK writes back into iparam during the iteration.

MultiEigSolution

Multi-eigenpair result returned by the eigenpairs_* drivers.

Enums

Which

Ritz value selector passed to ARPACK’s *aupd_c which parameter.