Struct Quantity 

pub struct Quantity { /* private fields */ }

A physical quantity: a numeric value with an associated unit.

Arithmetic

• Multiplication and division always succeed and combine dimensions automatically (e.g., m * m → m², m / s → m·s⁻¹).
• Addition and subtraction via + and - panic if the two quantities have incompatible dimensions. Use checked_add and checked_sub for fallible versions that return Result.

Examples

use iridium_units::prelude::*;

let distance = 100.0 * M;
let time = 9.58 * S;
let speed = &distance / &time;

let speed_kmh = speed.to(&(KM / H)).unwrap();

Implementations

impl Quantity

pub fn new(value: f64, unit: Unit) -> Self

Create a new quantity with a value and unit.

pub fn value(&self) -> f64

Get the numeric value.

pub fn unit(&self) -> &Unit

Get the unit.

pub fn is_dimensionless(&self) -> bool

Check if this quantity is dimensionless.

pub fn dimensionless_value(&self) -> UnitResult<f64>

Get the value as a dimensionless scalar.

Returns Err if the quantity is not dimensionless.

pub fn to(&self, target: impl Into<Unit>) -> UnitResult<Quantity>

Convert to another unit.

Returns Err if the units have incompatible dimensions.

pub fn to_value(&self, target: impl Into<Unit>) -> UnitResult<f64>

Get the value in a target unit.

Shorthand for .to(target)?.value().

pub fn decompose(&self) -> Quantity

Decompose to SI base units.

pub fn pow(&self, exp: impl Into<Rational16>) -> Quantity

Raise this quantity to a power.

Accepts any type convertible to Rational16, including Rational16 itself. When passing an i32, the value must fit in i16 range.

Uses powi for integer exponents and powf for fractional exponents.

pub fn sqrt(&self) -> Quantity

Take the square root of this quantity.

pub fn abs(&self) -> Quantity

Get the absolute value of this quantity.

pub fn is_logarithmic(&self) -> bool

Check if this quantity has a logarithmic unit (magnitude dimension).

Logarithmic units include magnitudes, decibels, and dex.

Example

use iridium_units::prelude::*;
use iridium_units::systems::logarithmic::MAG;

let mag = 5.0 * MAG;
assert!(mag.is_logarithmic());

let length = 10.0 * M;
assert!(!length.is_logarithmic());

pub fn mag_to_flux_ratio(&self) -> UnitResult<f64>

Convert a magnitude quantity to a flux ratio.

Uses the Pogson formula: F/F₀ = 10^(-0.4 * m)

Returns Err if this quantity does not have magnitude dimension.

Example

use iridium_units::prelude::*;
use iridium_units::systems::logarithmic::MAG;

let star = 5.0 * MAG;  // 5th magnitude
let flux = star.mag_to_flux_ratio().unwrap();
assert!((flux - 0.01).abs() < 1e-10);  // 1/100 of reference flux

pub fn db_to_power_ratio(&self) -> UnitResult<f64>

Convert a decibel quantity to a power ratio.

Uses the formula: P/P₀ = 10^(dB/10)

Returns Err if this quantity does not have magnitude dimension.

Example

use iridium_units::prelude::*;
use iridium_units::systems::logarithmic::DB;

let signal = 10.0 * DB;  // 10 dB
let power = signal.db_to_power_ratio().unwrap();
assert!((power - 10.0).abs() < 1e-10);  // 10x power

pub fn dex_to_ratio(&self) -> UnitResult<f64>

Convert a dex quantity to a linear ratio.

Uses the formula: x/x₀ = 10^dex

Returns Err if this quantity does not have magnitude dimension.

Example

use iridium_units::prelude::*;
use iridium_units::systems::logarithmic::DEX;

let order = 2.0 * DEX;  // 2 orders of magnitude
let ratio = order.dex_to_ratio().unwrap();
assert!((ratio - 100.0).abs() < 1e-10);  // factor of 100

impl Quantity

pub fn checked_add(&self, rhs: &Quantity) -> UnitResult<Quantity>

Add two quantities, returning an error if their dimensions don’t match.

This is the fallible version of the + operator.

use iridium_units::prelude::*;

let a = 1.0 * KM;
let b = 500.0 * M;
let c = a.checked_add(&b).unwrap();
assert!((c.value() - 1.5).abs() < 1e-10);

pub fn checked_sub(&self, rhs: &Quantity) -> UnitResult<Quantity>

Subtract two quantities, returning an error if their dimensions don’t match.

This is the fallible version of the - operator.

use iridium_units::prelude::*;

let a = 1.0 * KM;
let b = 500.0 * M;
let c = a.checked_sub(&b).unwrap();
assert!((c.value() - 0.5).abs() < 1e-10);

impl Quantity

pub fn to_equiv( &self, target: impl Into<Unit>, equiv: Equivalency, ) -> UnitResult<Quantity>

Convert to another unit using equivalencies.

First tries a direct dimensional conversion. If that fails, tries each equivalency in order until one succeeds.

pub fn to_equiv_list( &self, target: impl Into<Unit>, equivs: &[Equivalency], ) -> UnitResult<Quantity>

Convert to another unit using a list of equivalencies.

Trait Implementations

impl Add for &Quantity

type Output = Quantity

The resulting type after applying the + operator.

fn add(self, rhs: &Quantity) -> Quantity

Performs the + operation.

impl Add for Quantity

type Output = Quantity

The resulting type after applying the + operator.

fn add(self, rhs: Quantity) -> Quantity

Performs the + operation.

impl Clone for Quantity

fn clone(&self) -> Quantity

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Quantity

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

Formats the value using the given formatter.

impl Display for Quantity

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

Formats the value using the given formatter.

impl Div<&Quantity> for Quantity

type Output = Quantity

The resulting type after applying the / operator.

fn div(self, rhs: &Quantity) -> Quantity

Performs the / operation.

impl Div<&Quantity> for f64

type Output = Quantity

The resulting type after applying the / operator.

fn div(self, rhs: &Quantity) -> Quantity

Performs the / operation.

impl Div<&Unit> for &Quantity

type Output = Quantity

The resulting type after applying the / operator.

fn div(self, unit: &Unit) -> Quantity

Performs the / operation.

impl Div<&Unit> for Quantity

type Output = Quantity

The resulting type after applying the / operator.

fn div(self, unit: &Unit) -> Quantity

Performs the / operation.

impl Div<BaseUnit> for &Quantity

type Output = Quantity

The resulting type after applying the / operator.

fn div(self, unit: BaseUnit) -> Quantity

Performs the / operation.

impl Div<BaseUnit> for Quantity

type Output = Quantity

The resulting type after applying the / operator.

fn div(self, unit: BaseUnit) -> Quantity

Performs the / operation.

impl Div<Quantity> for &Quantity

type Output = Quantity

The resulting type after applying the / operator.

fn div(self, rhs: Quantity) -> Quantity

Performs the / operation.

impl Div<Quantity> for f64

type Output = Quantity

The resulting type after applying the / operator.

fn div(self, rhs: Quantity) -> Quantity

Performs the / operation.

impl Div<Unit> for &Quantity

type Output = Quantity

The resulting type after applying the / operator.

fn div(self, unit: Unit) -> Quantity

Performs the / operation.

impl Div<Unit> for Quantity

type Output = Quantity

The resulting type after applying the / operator.

fn div(self, unit: Unit) -> Quantity

Performs the / operation.

impl Div<f64> for &Quantity

type Output = Quantity

The resulting type after applying the / operator.

fn div(self, rhs: f64) -> Quantity

Performs the / operation.

impl Div<f64> for Quantity

type Output = Quantity

The resulting type after applying the / operator.

fn div(self, rhs: f64) -> Quantity

Performs the / operation.

impl Div for &Quantity

type Output = Quantity

The resulting type after applying the / operator.

fn div(self, rhs: &Quantity) -> Quantity

Performs the / operation.

impl Div for Quantity

type Output = Quantity

The resulting type after applying the / operator.

fn div(self, rhs: Quantity) -> Quantity

Performs the / operation.

impl FromStr for Quantity

type Err = UnitError

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Mul<&Quantity> for Quantity

type Output = Quantity

The resulting type after applying the * operator.

fn mul(self, rhs: &Quantity) -> Quantity

Performs the * operation.

impl Mul<&Quantity> for f64

type Output = Quantity

The resulting type after applying the * operator.

fn mul(self, rhs: &Quantity) -> Quantity

Performs the * operation.

impl Mul<&Unit> for &Quantity

type Output = Quantity

The resulting type after applying the * operator.

fn mul(self, unit: &Unit) -> Quantity

Performs the * operation.

impl Mul<&Unit> for Quantity

type Output = Quantity

The resulting type after applying the * operator.

fn mul(self, unit: &Unit) -> Quantity

Performs the * operation.

impl Mul<BaseUnit> for &Quantity

type Output = Quantity

The resulting type after applying the * operator.

fn mul(self, unit: BaseUnit) -> Quantity

Performs the * operation.

impl Mul<BaseUnit> for Quantity

type Output = Quantity

The resulting type after applying the * operator.

fn mul(self, unit: BaseUnit) -> Quantity

Performs the * operation.

impl Mul<Quantity> for &Quantity

type Output = Quantity

The resulting type after applying the * operator.

fn mul(self, rhs: Quantity) -> Quantity

Performs the * operation.

impl Mul<Quantity> for f64

type Output = Quantity

The resulting type after applying the * operator.

fn mul(self, rhs: Quantity) -> Quantity

Performs the * operation.

impl Mul<Unit> for &Quantity

type Output = Quantity

The resulting type after applying the * operator.

fn mul(self, unit: Unit) -> Quantity

Performs the * operation.

impl Mul<Unit> for Quantity

type Output = Quantity

The resulting type after applying the * operator.

fn mul(self, unit: Unit) -> Quantity

Performs the * operation.

impl Mul<f64> for &Quantity

type Output = Quantity

The resulting type after applying the * operator.

fn mul(self, rhs: f64) -> Quantity

Performs the * operation.

impl Mul<f64> for Quantity

type Output = Quantity

The resulting type after applying the * operator.

fn mul(self, rhs: f64) -> Quantity

Performs the * operation.

impl Mul for &Quantity

type Output = Quantity

The resulting type after applying the * operator.

fn mul(self, rhs: &Quantity) -> Quantity

Performs the * operation.

impl Mul for Quantity

type Output = Quantity

The resulting type after applying the * operator.

fn mul(self, rhs: Quantity) -> Quantity

Performs the * operation.

impl Neg for &Quantity

type Output = Quantity

The resulting type after applying the - operator.

fn neg(self) -> Quantity

Performs the unary - operation.

impl Neg for Quantity

type Output = Quantity

The resulting type after applying the - operator.

fn neg(self) -> Quantity

Performs the unary - operation.

impl PartialEq for Quantity

fn eq(&self, other: &Self) -> 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 Sub for &Quantity

type Output = Quantity

The resulting type after applying the - operator.

fn sub(self, rhs: &Quantity) -> Quantity

Performs the - operation.

impl Sub for Quantity

type Output = Quantity

The resulting type after applying the - operator.

fn sub(self, rhs: Quantity) -> Quantity

Performs the - operation.