Struct DecimationTransformation 

pub struct DecimationTransformation {
    pub k: f64,
    pub ln_lambda: f64,
    pub steps: usize,
}

1-D Ising decimation RG transformation.

The partition function of the 1-D Ising model with coupling K is reproduced by a system with half as many spins and an effective coupling K’. The recursion relation is: K’ = (1/2) ln cosh(2K)

Fields

k: f64

Current coupling K = J/(k_B T).

ln_lambda: f64

Current additive constant (free energy per site contribution).

steps: usize

Number of decimation steps performed.

Implementations

impl DecimationTransformation

pub fn new(k0: f64) -> Self

Construct a decimation RG at coupling K₀.

pub fn step(&mut self)

Perform one step of 1-D Ising decimation.

K’ = (1/2) ln cosh(2K), ln λ += (1/2) ln[4 cosh(2K)]

pub fn run(&mut self, n: usize)

Run n decimation steps.

pub fn correlation_length(&self) -> f64

Correlation length after decimation (rough estimate via K).

ξ = −1 / ln tanh(K)

pub fn trajectory(&self, n: usize) -> Vec<f64>

Collect K trajectory over n steps.

pub fn migdal_kadanoff_step(&mut self, b: u32)

2-D block-spin decimation flow for the square Ising model (Migdal-Kadanoff).

K’ = (1/2) ln cosh(2bK) where b = 2 is the block factor.

Trait Implementations

impl Clone for DecimationTransformation

fn clone(&self) -> DecimationTransformation

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DecimationTransformation

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

Formats the value using the given formatter.