Struct Variance 

pub struct Variance(pub f64);

A distribution parameter that uses the variance as representation

Example:

use concrete_core::prelude::{DispersionParameter, Variance};
let params = Variance::from_variance(2_f64.powi(-50));
assert_eq!(params.get_standard_dev(), 2_f64.powf(-25.));
assert_eq!(params.get_log_standard_dev(), -25.);
assert_eq!(params.get_variance(), 2_f64.powf(-25.).powi(2));
assert_eq!(params.get_modular_standard_dev(32), 2_f64.powf(32. - 25.));
assert_eq!(params.get_modular_log_standard_dev(32), 32. - 25.);
assert_eq!(
    params.get_modular_variance(32),
    2_f64.powf(32. - 25.).powi(2)
);

Tuple Fields

0: f64

Implementations

impl Variance

pub fn from_variance(var: f64) -> Variance

pub fn from_modular_variance(var: f64, log2_modulus: u32) -> Variance

Trait Implementations

impl Clone for Variance

fn clone(&self) -> Variance

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Variance

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

Formats the value using the given formatter.

impl DispersionParameter for Variance

fn get_standard_dev(&self) -> f64

Returns the standard deviation of the distribution, i.e. $\sigma = 2^p$.

fn get_variance(&self) -> f64

Returns the variance of the distribution, i.e. $\sigma^2 = 2^{2p}$.

fn get_log_standard_dev(&self) -> f64

Returns base 2 logarithm of the standard deviation of the distribution, i.e. $\log_2(\sigma)=p$

fn get_modular_standard_dev(&self, log2_modulus: u32) -> f64

For a Uint type representing $\mathbb{Z}/2^q\mathbb{Z}$, we return $2^{q-p}$.

fn get_modular_variance(&self, log2_modulus: u32) -> f64

For a Uint type representing $\mathbb{Z}/2^q\mathbb{Z}$, we return $2^{2(q-p)}$.

fn get_modular_log_standard_dev(&self, log2_modulus: u32) -> f64

For a Uint type representing $\mathbb{Z}/2^q\mathbb{Z}$, we return $q-p$.

impl PartialEq for Variance

fn eq(&self, other: &Variance) -> 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 PartialOrd for Variance

fn partial_cmp(&self, other: &Variance) -> 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 Copy for Variance

impl StructuralPartialEq for Variance