Enum ArpackError 

pub enum ArpackError {
    NoError,
    Prod,
    NPos,
    NevNPos,
    NcvSmall,
    NonPosI,
    WhichInv,
    BmatInv,
    WorklSmall,
    TriDErr,
    ZeroStart,
    ModeInv,
    ModeBmat,
    IShift,
    NevBe,
    NoFact,
    Failed,
    Howmny,
    HowmnyS,
    EvDiff,
    Shur,
    Lapack,
    Unknown,
    MaxIt,
    NoShift,
    Reorder,
}

Error conditions reported by ARPACK (igraph_arpack_error_t), see ArpackError::from_error and arpack_error_to_string.

Variants

NoError

No error.

Prod

Matrix-vector product failed (not used any more).

NPos

N must be positive.

NevNPos

NEV must be positive.

NcvSmall

NCV must be bigger.

NonPosI

Maximum number of iterations should be positive.

WhichInv

Invalid WHICH parameter.

BmatInv

Invalid BMAT parameter.

WorklSmall

WORKL is too small.

TriDErr

LAPACK error in tridiagonal eigenvalue calculation.

ZeroStart

Starting vector is zero.

ModeInv

MODE is invalid.

ModeBmat

MODE and BMAT are not compatible.

IShift

ISHIFT must be 0 or 1.

NevBe

NEV and WHICH=‘BE’ are incompatible.

NoFact

Could not build an Arnoldi factorization.

Failed

No eigenvalues to sufficient accuracy.

Howmny

HOWMNY is invalid.

HowmnyS

HOWMNY=‘S’ is not implemented.

EvDiff

Different number of converged Ritz values.

Shur

Error from calculation of a real Schur form.

Lapack

LAPACK (dtrevc) error for calculating eigenvectors.

Unknown

Unknown ARPACK error.

MaxIt

Maximum number of iterations reached.

NoShift

No shifts could be applied during a cycle of the implicitly restarted Arnoldi iteration.

Reorder

The Schur form could not be reordered.

Implementations

impl ArpackError

pub fn from_error(error: &Error) -> Option<Self>

The ARPACK error condition behind an ErrorKind::Arpack error, recognized from its message (igraph reports ARPACK failures with the text of arpack_error_to_string); None for other errors.

Unlike arpack_last_error this is thread-safe: it only looks at the error value returned by the failed call.

use igraph::{linalg::*, ErrorKind};
// The Laplacian of a path, started from its eigenvector (1, ..., 1) of
// eigenvalue 0: ARPACK's first Krylov vector is zero.
let n = 6;
let path = move |x: &[f64], y: &mut [f64]| {
    for i in 0..n {
        let deg = if i == 0 || i == n - 1 { 1.0 } else { 2.0 };
        y[i] = deg * x[i];
        if i > 0 {
            y[i] -= x[i - 1];
        }
        if i + 1 < n {
            y[i] -= x[i + 1];
        }
    }
};
let opts = ArpackOptions::default()
    .with_start(vec![1.0; n])
    .with_which(ArpackWhich::SmallestMagnitude);
let err = arpack_rssolve(n, path, &opts, None).unwrap_err();
assert_eq!(err.kind(), ErrorKind::Arpack);
assert_eq!(ArpackError::from_error(&err), Some(ArpackError::ZeroStart));

Trait Implementations

impl Clone for ArpackError

fn clone(&self) -> ArpackError

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for ArpackError

impl Debug for ArpackError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for ArpackError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for ArpackError

impl From<ArpackError> for igraph_arpack_error_t

fn from(value: ArpackError) -> igraph_arpack_error_t

Converts to this type from the input type.

impl Hash for ArpackError

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ArpackError

fn eq(&self, other: &ArpackError) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for ArpackError

impl TryFrom<u32> for ArpackError

type Error = Error

The type returned in the event of a conversion error.

fn try_from(value: igraph_arpack_error_t) -> Result<Self>

Performs the conversion.