Struct PhysicalConstant 

pub struct PhysicalConstant {
    pub value: f64,
    pub uncertainty: f64,
    pub unit: &'static str,
    pub symbol: &'static str,
    pub name: &'static str,
}

A physical constant with its value, uncertainty, unit, symbol, and name.

This struct represents a NIST/CODATA physical constant with full metadata. Constants that are exact (zero uncertainty) under the 2019 SI redefinition are indicated by uncertainty = 0.0.

Fields

• value - The numerical value of the constant in SI units
• uncertainty - The standard uncertainty (0.0 for exact constants)
• unit - The SI unit string (e.g., “m/s”, “J s”)
• symbol - The conventional symbol (e.g., “c”, “h”, “k_B”)
• name - The full descriptive name of the constant

Fields

value: f64

The numerical value of the constant in SI units

uncertainty: f64

The standard uncertainty (0.0 for exact constants)

unit: &'static str

The SI unit string

symbol: &'static str

The conventional symbol

name: &'static str

The full descriptive name

Implementations

impl PhysicalConstant

pub fn relative_uncertainty(&self) -> f64

Returns the relative uncertainty of this constant.

For exact constants (uncertainty = 0.0), this returns 0.0. For non-exact constants, this returns uncertainty / |value|.

Examples

use numrs2::new_modules::constants::GRAVITATIONAL_CONSTANT;
let rel = GRAVITATIONAL_CONSTANT.relative_uncertainty();
assert!(rel > 0.0); // G has nonzero uncertainty

pub fn is_exact(&self) -> bool

Returns true if this constant is exact (zero uncertainty).

Under the 2019 SI redefinition, several fundamental constants (speed of light, Planck constant, elementary charge, Boltzmann constant, Avogadro constant) have exact defined values.

Trait Implementations

impl Clone for PhysicalConstant

fn clone(&self) -> PhysicalConstant

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for PhysicalConstant

impl Debug for PhysicalConstant

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

Formats the value using the given formatter.

impl Display for PhysicalConstant

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

Formats the value using the given formatter.

impl PartialEq for PhysicalConstant

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