Crate dashu_ratio

source ·
Expand description

A big rational library with good performance.

The library implements efficient arithmetic and conversion functions in pure Rust.

The two main rational types are RBig and Relaxed. Both of them represent the rational number as a pair of integers (numerator and denominator) and their APIs are mostly the same. However only with RBig, the numerator and denominator are reduced so that they don’t have common divisors other than one. Therefore, Relaxed sometimes can be much faster if you don’t care about a reduced representation of the rational number. However, benchmarking is always recommended before choosing which representation to use.

To construct big rationals from literals, please use the dashu-macro crate for your convenience.

Examples

use dashu_int::{IBig, UBig};
use dashu_ratio::{RBig, Relaxed};

let a = RBig::from_parts((-12).into(), 34u8.into());
let b = RBig::from_str_radix("-azz/ep", 36).unwrap();
let c = RBig::try_from(3.1415926f32).unwrap(); // c = 6588397 / 2097152 (lossless)
let c2 = RBig::simplest_from_f32(3.1415926).unwrap(); // c2 = 51808 / 16491
assert_eq!(c2.numerator(), &IBig::from(51808));

assert_eq!(c.to_string(), "6588397/2097152");
let d = RBig::simplest_from_f32(22./7.).unwrap();
assert_eq!(d.to_string(), "22/7"); // round trip to the original literal

// for Relaxed, only the common divisor 2 is removed
let e: Relaxed = "-3228/1224".parse()?; // d = -807 / 306
assert_eq!(e.numerator(), &IBig::from(-807));
let f: RBig = e.clone().canonicalize(); // e = -269 / 102
assert_eq!(f.numerator(), &IBig::from(-269));

Modules

  • ops
    Re-exported relevant operator traits from dashu-base
  • rand
    Random rational numbers generation with the rand crate.

Structs

  • RBig
    An arbitrary precision rational number.
  • Relaxed
    An arbitrary precision rational number without strict reduction.