Enum ContractionAlgorithm 

#[repr(i32)]
pub enum ContractionAlgorithm {
    Naive = 0,
    ZipUp = 1,
    Fit = 2,
}

Algorithm for tensor train contraction (TT-TT or MPO-MPO).

These algorithms contract two tensor trains and produce a new tensor train, optionally with compression/truncation.

C API Representation

• T4A_CONTRACT_NAIVE = 0
• T4A_CONTRACT_ZIPUP = 1
• T4A_CONTRACT_FIT = 2

Variants

Naive = 0

Naive contraction followed by compression.

Contracts all site tensors first (producing large intermediate tensors), then compresses the result. Exact up to compression tolerance.

Memory: O(D^4) where D is the bond dimension.

ZipUp = 1

Zip-up contraction with on-the-fly compression.

Contracts and compresses site-by-site, keeping bond dimensions small. More memory efficient than naive, but may introduce additional error.

Memory: O(D^2)

Fit = 2

Variational fitting algorithm.

Optimizes the result tensor train to minimize the distance to the exact contraction. Uses sweeping optimization.

Best for cases where target bond dimension is much smaller than the exact result.

Implementations

impl ContractionAlgorithm

pub fn from_i32(value: i32) -> Option<Self>

Create from C API integer representation.

Returns None for invalid values.

pub fn to_i32(self) -> i32

Convert to C API integer representation.

pub fn name(&self) -> &'static str

Get algorithm name as string.

Trait Implementations

impl Clone for ContractionAlgorithm

fn clone(&self) -> ContractionAlgorithm

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ContractionAlgorithm

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

Formats the value using the given formatter.

impl Default for ContractionAlgorithm

fn default() -> ContractionAlgorithm

Returns the “default value” for a type.

impl Hash for ContractionAlgorithm

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 ContractionAlgorithm

fn eq(&self, other: &ContractionAlgorithm) -> 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 Copy for ContractionAlgorithm

impl Eq for ContractionAlgorithm

impl StructuralPartialEq for ContractionAlgorithm