Struct predicates::float::IsClosePredicate

pub struct IsClosePredicate { /* private fields */ }

Available on crate feature float-cmp only.

Predicate that ensures two numbers are “close” enough, understanding that rounding errors occur.

This is created by the predicate::float::is_close.

Implementations

impl IsClosePredicate

pub fn distance(self, distance: <f64 as Ulps>::U) -> Self

Set the amount of error allowed.

Values 1-5 should work in most cases. Sometimes more control is needed and you will need to set IsClosePredicate::epsilon separately from IsClosePredicate::ulps.

Examples

use predicates::prelude::*;

let a = 0.15_f64 + 0.15_f64 + 0.15_f64;
let predicate_fn = predicate::float::is_close(a).distance(5);

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

Set the absolute deviation allowed.

This is meant to handle problems near 0. Values 1.-5. epislons should work in most cases.

Examples

use predicates::prelude::*;

let a = 0.15_f64 + 0.15_f64 + 0.15_f64;
let predicate_fn = predicate::float::is_close(a).epsilon(5.0 * f64::EPSILON);

pub fn ulps(self, ulps: <f64 as Ulps>::U) -> Self

Set the relative deviation allowed.

This is meant to handle large numbers. Values 1-5 should work in most cases.

Examples

use predicates::prelude::*;

let a = 0.15_f64 + 0.15_f64 + 0.15_f64;
let predicate_fn = predicate::float::is_close(a).ulps(5);

Trait Implementations

impl Clone for IsClosePredicate

fn clone(&self) -> IsClosePredicate

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for IsClosePredicate

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

Formats the value using the given formatter.

impl Display for IsClosePredicate

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

Formats the value using the given formatter.

impl PartialEq for IsClosePredicate

fn eq(&self, other: &IsClosePredicate) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Predicate<f64> for IsClosePredicate

fn eval(&self, variable: &f64) -> bool

Execute this Predicate against variable, returning the resulting boolean.

fn find_case<'a>(&'a self, expected: bool, variable: &f64) -> Option<Case<'a>>

Find a case that proves this predicate as expected when run against variable.

impl PredicateReflection for IsClosePredicate

fn parameters<'a>(&'a self) -> Box<dyn Iterator<Item = Parameter<'a>> + 'a>

Parameters of the current Predicate.

fn children<'a>(&'a self) -> Box<dyn Iterator<Item = Child<'a>> + 'a>

Nested Predicates of the current Predicate.

impl Copy for IsClosePredicate

impl StructuralPartialEq for IsClosePredicate