Struct MatsubaraFreq 

pub struct MatsubaraFreq<S: StatisticsType> { /* private fields */ }

Matsubara frequency for a specific statistics type

This represents the Matsubara frequency ν = nπ/β, where:

• n is the stored integer (the reduced Matsubara frequency, returned by n): odd for fermionic statistics (n = ±1, ±3, …) and even for bosonic statistics (n = 0, ±2, ±4, …)
• β is the inverse temperature, passed to value and value_imaginary

In terms of the conventional Matsubara index m of ν = (2m + ζ)π/β, with ζ = 1 for fermionic and ζ = 0 for bosonic statistics, the stored integer is n = 2m + ζ; it is not m itself. new rejects an n whose parity does not match the statistics.

The statistics type S is checked at compile time to ensure type safety.

Examples

use sparse_ir::{BosonicFreq, FermionicFreq};
use std::f64::consts::PI;

let beta = 10.0;

// n = 1 is the lowest positive fermionic frequency, ω = π/β (k = 0).
let w = FermionicFreq::new(1).unwrap();
assert_eq!(w.n(), 1);
assert!((w.value(beta) - PI / beta).abs() < 1e-15);

// n = 2 is the lowest positive bosonic frequency, ω = 2π/β (k = 1).
let nu = BosonicFreq::new(2).unwrap();
assert!((nu.value(beta) - 2.0 * PI / beta).abs() < 1e-15);

// The parity of n must match the statistics.
assert!(FermionicFreq::new(2).is_err());
assert!(BosonicFreq::new(1).is_err());

Adding or subtracting frequencies gives the statistics of the result: FermionicFreq ± FermionicFreq is a BosonicFreq, and a fermionic and a bosonic frequency (in either order) give a FermionicFreq.

Implementations

impl<S: StatisticsType> MatsubaraFreq<S>

pub fn n(&self) -> i64

Get the reduced Matsubara frequency n, where ν = nπ/β

n is odd for fermionic and even for bosonic statistics.

pub fn new(n: i64) -> Result<Self, Error>

Create a new Matsubara frequency

Arguments

• n - The reduced Matsubara frequency n of ν = nπ/β: odd for fermionic statistics, even for bosonic statistics

Errors

Error::InvalidMatsubaraIndex if n is even for fermionic or odd for bosonic statistics

Examples

use sparse_ir::freq::{FermionicFreq, BosonicFreq};

let fermionic = FermionicFreq::new(1).unwrap();  // OK: odd n for fermionic
let bosonic = BosonicFreq::new(0).unwrap();      // OK: even n for bosonic

pub unsafe fn new_unchecked(n: i64) -> Self

Create a Matsubara frequency without validation

Safety

This function bypasses the validation in new(). Only use when you’re certain the frequency is valid for the statistics type.

pub fn get_n(&self) -> i64

Get the reduced Matsubara frequency n, where ν = nπ/β (same as n)

pub fn value(&self, beta: f64) -> f64

Compute the real frequency value: n * π / β

Arguments

• beta - Inverse temperature

Returns

The real frequency value

pub fn value_imaginary(&self, beta: f64) -> Complex64

Compute the imaginary frequency value: i * n * π / β

Arguments

• beta - Inverse temperature

Returns

The imaginary frequency value as a complex number

pub fn statistics(&self) -> Statistics

Get the statistics type

pub fn into_i64(self) -> i64

Convert to i64 (for compatibility with C++ operator long long())

Trait Implementations

impl Add<MatsubaraFreq<Bosonic>> for FermionicFreq

type Output = MatsubaraFreq<Fermionic>

The resulting type after applying the + operator.

fn add(self, other: BosonicFreq) -> FermionicFreq

Performs the + operation.

impl Add<MatsubaraFreq<Fermionic>> for BosonicFreq

type Output = MatsubaraFreq<Fermionic>

The resulting type after applying the + operator.

fn add(self, other: FermionicFreq) -> FermionicFreq

Performs the + operation.

impl<S: Clone + StatisticsType> Clone for MatsubaraFreq<S>

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

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<S: Copy + StatisticsType> Copy for MatsubaraFreq<S>

impl<S: Debug + StatisticsType> Debug for MatsubaraFreq<S>

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

Formats the value using the given formatter.

impl<S: StatisticsType> Display for MatsubaraFreq<S>

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

Formats the value using the given formatter.

impl<S: StatisticsType> Eq for MatsubaraFreq<S>

impl<S: StatisticsType> From<MatsubaraFreq<S>> for i64

fn from(freq: MatsubaraFreq<S>) -> Self

Converts to this type from the input type.

impl<S: StatisticsType> Hash for MatsubaraFreq<S>

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<S: StatisticsType> Neg for MatsubaraFreq<S>

type Output = MatsubaraFreq<S>

The resulting type after applying the - operator.

fn neg(self) -> Self

Performs the unary - operation.

impl<S: StatisticsType> Ord for MatsubaraFreq<S>

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<S: StatisticsType> PartialEq for MatsubaraFreq<S>

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

Equality operator ==.

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

Inequality operator !=.

impl<S: StatisticsType> PartialOrd for MatsubaraFreq<S>

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Sub<MatsubaraFreq<Bosonic>> for FermionicFreq

type Output = MatsubaraFreq<Fermionic>

The resulting type after applying the - operator.

fn sub(self, other: BosonicFreq) -> FermionicFreq

Performs the - operation.

impl Sub<MatsubaraFreq<Fermionic>> for BosonicFreq

type Output = MatsubaraFreq<Fermionic>

The resulting type after applying the - operator.

fn sub(self, other: FermionicFreq) -> FermionicFreq

Performs the - operation.