Lib.rs

BIG NUM MATH

Library for computations on large numbers.

• development notes:
  1. little plan for new functions
  2. upcoming optimizations (memory consumption, speed up on some computations, …)
• functions only:
  • addition +substraction,
  • multiplication +division
  • relation and decimal relation operators
  • order of magnitude
  • power
  • integer square root
  • primality check
  • prime number generator (primitive number types only)

Usage Samples

power

let row = PlacesRow::new_from_u128(u128::MAX);
let pow = pow(&row, 500);
let number = pow.to_number();

assert!(number.starts_with("8312324609993336522"));
assert_eq!(19266, number.len());

division with remainder

let dividend = PlacesRow::new_from_str("3402823669209384634633746074317682114565556668744123").unwrap();
let divisor  = PlacesRow::new_from_str(  "14034568236692093846346337460345176821145655563453").unwrap();
let ratio = "242";        
let remainder = "6458155929897923817932408914149323848308022388497";
        
let ratrem = divrem(&dividend, &divisor).unwrap();
        
assert_eq!(ratio, ratrem.0.to_number());
assert_eq!(remainder, ratrem.1.to_number());

let dividend = Row::new_from_str("99999340282366920938463463374607431768211455").unwrap();
let divisor  = Row::new_from_usize(249);

let ratio     = Row::new_from_str("401603776234405304973748848894005750073138").unwrap();
let remainder = Row::new_from_usize(93);

let ratrem = divrem(&dividend, &divisor).unwrap();
assert_eq!(ratio, ratrem.0);
assert_eq!(remainder, ratrem.1);

decimal places relation

let number    = Row::new_from_str("1489754132134687989463132131").unwrap();
let comparand = Row::new_from_str(        "48645698946456531371").unwrap();
let decrel = rel_dec(&number, &comparand);

assert_eq!(RelDec::Greater((28, 20, 8)), decrel);

order of magnitude

let number_1 = PlacesRow::new_from_u128(3162277660168379331998893544432);
let number_2 = PlacesRow::new_from_u128(3162277660168379331998893544433);

assert_eq!(Oom::Precise(30), ord_of_mag(&number_1, OomKind::Strict));
assert_eq!(Oom::Precise(31), ord_of_mag(&number_2, OomKind::Strict));
assert_eq!(Oom::Precise(30), ord_of_mag(&number_2, OomKind::Loose));

square root

let test  = Row::new_from_str("9754610577924096936222542295378750190521").unwrap();
let proof = Row::new_from_u128(98_765_432_100_123_456_789);
assert_eq!(proof, heron_sqrt(&test));

primality check

let num = Row::new_from_str("340282366920938463463374607431768211479").unwrap();
let limit = Duration::from_secs(3);
assert_eq!(Some(false), prime_ck(&num, Some(limit)));

prime number generation

let limit = Duration::from_secs(60);
let p = || pg!(200_000, PrimeGenStrain::Nth, false, u32, Some(limit));
assert_eq!(2_750_159, p().uproot_max());