Struct BlockLanczosParams 

pub struct BlockLanczosParams {
    pub block_size: usize,
    pub basis_size: Option<usize>,
    pub max_restarts: usize,
    pub tol: f64,
}

Parameters for the block thick-restart Lanczos eigensolver.

Fields

block_size: usize

Vectors per block, i.e. the width of every operator call. Wider blocks mean fewer, larger calls, which is what pays where each call carries a fixed launch and readback cost. Capped at half the operator dimension.

basis_size: Option<usize>

Krylov basis vectors held at once, rounded down to whole blocks. None derives it as for LanczosParams, rounded up to whole blocks, at least twice the retained Ritz block and with room for BLOCK_LANCZOS_MIN_NEW_BLOCKS new blocks per cycle.

max_restarts: usize

Maximum restart cycles.

tol: f64

Relative residual tolerance, tested against tol * ||A|| as in LanczosParams::tol.

Implementations

impl BlockLanczosParams

pub fn new() -> Self

Defaults, chosen for the cubecl GPU path. Backends whose per-call cost grows faster with the block width override the block size.

Returns

Self with blocks of 32, a derived basis size, 64 restarts and a relative tolerance of 1e-6. That is tight enough that an f32 operator’s singular values agree with an f64 solve to f32 precision, while the scalar solver’s 1e-8 sits near the f32 round-off and would mostly burn the restart budget.

Trait Implementations

impl Clone for BlockLanczosParams

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for BlockLanczosParams

impl Debug for BlockLanczosParams

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

Formats the value using the given formatter.

impl Default for BlockLanczosParams

fn default() -> Self

Returns the “default value” for a type.