Struct Decibel 

pub struct Decibel {
    pub reference: f64,
    pub factor: f64,
}

A decibel scale: dB = factor · log10(linear / reference).

The factor is the whole difference between an amplitude quantity and a power one — twenty for volts, amperes and pressures, ten for watts — and mixing the two is the mistake this type exists to make unrepresentable.

Fields

reference: f64

The linear value that reads as zero decibels, in base units.

factor: f64

The log factor: twenty for amplitudes, ten for powers.

Implementations

impl Decibel

pub fn amplitude(reference: f64) -> Self

An amplitude scale — factor twenty — against a stated reference.

pub fn power(reference: f64) -> Self

A power scale — factor ten — against a stated reference.

pub fn volt() -> Self

dBV: amplitude against one volt.

pub fn millivolt() -> Self

dBmV: amplitude against one millivolt.

pub fn microvolt() -> Self

dBµV: amplitude against one microvolt, the electromagnetic-compatibility convention.

pub fn ampere() -> Self

dBA: amplitude against one ampere.

pub fn milliampere() -> Self

dBmA: amplitude against one milliampere.

pub fn microampere() -> Self

dBµA: amplitude against one microampere.

pub fn sound_pressure() -> Self

dB SPL: amplitude against twenty micropascals.

pub fn watt() -> Self

dBW: power against one watt.

pub fn milliwatt() -> Self

dBm: power against one milliwatt, the radio convention.

pub fn to_db(&self, linear: f64) -> f64

This linear value in decibels. Zero and below read as negative infinity.

pub fn to_linear(&self, db: f64) -> f64

This decibel value back in base units.

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

Whether two scales measure the same kind of quantity.

Same factor, any reference: dBµV and dBmV are one subtraction apart, dBV and dBm are not comparable at all.

pub fn offset_from(&self, other: &Self) -> Option<f64>

What to add to a value in other to read it in this scale.

Nothing, when the two measure different kinds of quantity.

Trait Implementations

impl Clone for Decibel

fn clone(&self) -> Decibel

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Decibel

impl Debug for Decibel

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

Formats the value using the given formatter.

impl PartialEq for Decibel

fn eq(&self, other: &Decibel) -> 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 StructuralPartialEq for Decibel