Struct LogProb 

pub struct LogProb(pub f64);

A probability stored as its natural logarithm: ln(p).

All values are ≤ 0 (since 0 < p ≤ 1), with 0.0 representing certainty (p = 1) and negative infinity representing impossibility (p = 0).

Tuple Fields

0: f64

Implementations

impl LogProb

pub fn from_prob(p: f64) -> Result<Self>

Create a LogProb from a raw probability in (0, 1].

Errors

Returns an error if p is not in (0, 1].

pub fn to_prob(self) -> f64

Convert back to a raw probability.

pub fn ln_add(self, other: Self) -> Self

Log-sum-exp: compute ln(exp(self) + exp(other)) without overflow.

This is the log-space equivalent of addition in probability space.

pub fn ln_mul(self, other: Self) -> Self

Multiply two probabilities in log-space (addition of log values).

pub const fn certain() -> Self

Certain event: ln(1) = 0.

pub const fn impossible() -> Self

Impossible event: ln(0) = -∞.

Trait Implementations

impl Clone for LogProb

fn clone(&self) -> LogProb

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LogProb

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

Formats the value using the given formatter.

impl From<LogProb> for PhredProb

fn from(lp: LogProb) -> Self

Convert LogProb → Phred: Q = -10 · log₁₀(p) = -ln(p) · 10 / ln(10).

impl From<PhredProb> for LogProb

fn from(phred: PhredProb) -> Self

Convert Phred → LogProb: ln(p) = -Q · ln(10) / 10.

impl PartialEq for LogProb

fn eq(&self, other: &LogProb) -> 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 LogProb

fn partial_cmp(&self, other: &LogProb) -> 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 LogProb

impl StructuralPartialEq for LogProb