Struct PiecewiseLegendreFT 

pub struct PiecewiseLegendreFT<S>
where
    S: StatisticsType,
{ /* private fields */ }

Piecewise Legendre polynomial with Fourier transform capability

This represents a piecewise Legendre polynomial that can be evaluated in the Matsubara frequency domain using Fourier transform.

Implementations

impl<S> PiecewiseLegendreFT<S>

where S: StatisticsType,

pub fn new( poly: PiecewiseLegendrePoly, _stat: S, n_asymp: Option<f64>, ) -> Result<PiecewiseLegendreFT<S>, Error>

Create a new PiecewiseLegendreFT from a polynomial and statistics

Arguments

• poly - The underlying piecewise Legendre polynomial
• stat - Statistics type (Fermionic or Bosonic)
• n_asymp - Asymptotic cutoff frequency index (default: infinity)

Errors

• Error::InvalidParameter if the domain of poly is not [-1, 1] within 1e-12, or n_asymp is NaN or negative (infinity, the default, disables the asymptotic model)

pub fn get_n_asymp(&self) -> f64

Get the asymptotic cutoff frequency index

pub fn get_statistics(&self) -> Statistics

Get the statistics type

pub fn zeta(&self) -> i64

Get the zeta value for this statistics type

pub fn get_poly(&self) -> &PiecewiseLegendrePoly

Get a reference to the underlying polynomial

pub fn evaluate(&self, omega: &MatsubaraFreq<S>) -> Complex<f64>

Evaluate the Fourier transform at a Matsubara frequency

Arguments

• omega - Matsubara frequency

Returns

The complex Fourier transform value

pub fn evaluate_at_n(&self, n: i64) -> Result<Complex<f64>, Error>

Evaluate at integer Matsubara index

Errors

Error::InvalidMatsubaraIndex if n has the wrong parity for the statistics (it returned 0 before)

pub fn evaluate_at_ns(&self, ns: &[i64]) -> Result<Vec<Complex<f64>>, Error>

Evaluate at multiple Matsubara indices

Errors

The error of Self::evaluate_at_n for the first invalid index

pub fn get_tnl(l: i32, w: f64) -> Complex<f64>

Get T_nl coefficient (special function)

This implements the T_nl function which is related to spherical Bessel functions: T_nl(w) = 2 * i^l * j_l(|w|) * (w < 0 ? conj : identity) where j_l is the spherical Bessel function of the first kind.

Trait Implementations

impl<S> Clone for PiecewiseLegendreFT<S>

where S: Clone + StatisticsType,

fn clone(&self) -> PiecewiseLegendreFT<S>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<S> Debug for PiecewiseLegendreFT<S>

where S: Debug + StatisticsType,

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

Formats the value using the given formatter.