Struct float_cmp::F64Margin

pub struct F64Margin {
    pub epsilon: f64,
    pub ulps: i64,
}

This type defines a margin within two f64 values might be considered equal, and is intended as the associated type for the ApproxEq trait.

Two tests are used to determine approximate equality.

The first test considers two values approximately equal if they differ by <= epsilon. This will only succeed for very small numbers. Note that it may succeed even if the parameters are of differing signs, straddling zero.

The second test considers how many ULPs (units of least precision, units in the last place, which is the integer number of floating-point representations that the parameters are separated by) different the parameters are and considers them approximately equal if this is <= ulps. For large floating-point numbers, an ULP can be a rather large gap, but this kind of comparison is necessary because floating-point operations must round to the nearest representable value and so larger floating-point values accumulate larger errors.

Fields

epsilon: f64

ulps: i64

Implementations

impl F64Margin

pub fn zero() -> F64Margin

pub fn epsilon(self, epsilon: f64) -> Self

pub fn ulps(self, ulps: i64) -> Self

Trait Implementations

impl Clone for F64Margin

fn clone(&self) -> F64Margin

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for F64Margin

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

Formats the value using the given formatter.

impl Default for F64Margin

fn default() -> F64Margin

Returns the “default value” for a type.

impl From<(f64, i64)> for F64Margin

fn from(m: (f64, i64)) -> F64Margin

Converts to this type from the input type.

impl Copy for F64Margin