Daninet
ExactNumber
Arbitrary-precision decimals. Enables making math calculations with rational numbers, without precision loss.
Features
- Works with arbitrary large numbers without precision loss
- All fractions can be represented as repeating decimals like
1.23(45) - This repeating decimal format (
1.23(45)) can also be parsed back - Works with all number bases between
2and16 - No special values like
NaN,Infinityor-0. - No silent errors: it throws errors immediatelly when a confusing parameter is received (e.g. 0/0)
- Supports bitwise operators (
and,or,xor,shiftLeft,shiftRight) - Includes approximation algorithms for irrational numbers like
PI,sin(1). - Supports all modern browsers, web workers, Node.js and Deno
- Includes TypeScript type definitions: documentation
- Zero external dependencies
- Under the hood, it relies on the
BigInttype. It automatically switches back and forth between fixed-precision and fractional representations. - Tries to deliver the best possible performance
- 100% open source + MIT license
Comparision with built-in numbers
import { ExactNumber as N } from 'exactnumber';
1 + 0.36 // 1.3599999999999999
N(1).add('0.36').toString() // 1.36
(1 / 49) * 49 // 0.9999999999999999
N(1).div(49).mul(49).toString() // 1
10e16 + 5 // 100000000000000000
N('10e16').add(5).toString() // 100000000000000005
1 / 3 // 0.3333333333333333
N(1).div(3).toString() // 0.(3)
2**32 >> 32 // 0
N(2).pow(32).shiftRight(32).toString() // 1Installation
npm i exactnumberIt can also be used directly from HTML (via jsDelivr):
<!-- loads the full, minified library into the global `exactnumber` variable -->
<script src="https://cdn.jsdelivr.net/npm/exactnumber"></script>
<!-- or loads the non-minified library -->
<script src="https://cdn.jsdelivr.net/npm/exactnumber/dist/index.umd.js"></script>Usage
import { ExactNumber as N } from 'exactnumber';
N(1).add('3').toString(); // 4
N('1/7').add('1/10').toFraction(); // 17/70
N('1/7').toString(); // 0.(142857)
N('1/7').toString(6); // 0.(05)
N('1/7').toFixed(3); // 0.142
N('1/7').trunc(3).toString(); // 0.142
N('0.(3)').add('0.(6)').toString(); // 1
N('0b1100').bitwiseAnd('0b1010').toString(2); // 1000
N.max('1/1', '10/2', 3).toString(); // 5
N.fromBase('123', 4).toString(); // 27
// approximations
import { PI, sin, pow } from 'exactnumber';
PI(10).toString(); // 3.1415926535
const PI_OVER_2 = PI(10).div(2);
sin(PI_OVER_2, 5).toString(); // 1.00000
// 0.1232323 raised to the power of 2.193333, approximated with 10 decimals
pow('0.1(23)', '2.19(3)', 10).toString(); // 0.0101310867Functions
- Addition / subtraction:
add(),sub() - Multiplication / division:
mul(),div(),divToInt() - Exponentiation:
pow() - Modular arithmetic:
mod(),powm() - Getting the sign / absolute value:
sign(),abs() - Negation / inversion:
neg(),inv() - Integer and fractional parts:
intPart(),fracPart() - Comparisons:
cmp(),eq(),lt(),lte(),gt(),gte() - Special comparisons:
isZero(),isOne() - Type testing:
isInteger() - Rounding:
round(),roundToDigits(),floor(),ceil(),trunc() - Bitwise operators:
bitwiseAnd(),bitwiseOr(),bitwiseXor(),shiftLeft(),shiftRight() - Clamping:
clamp() - Fraction helper:
getFractionParts() - Normalization / simplifying fractions:
normalize() - String output:
toFixed(),toExponential(),toPrecision(),toString(),toFraction() - Number output:
toNumber() - GCD, LCM:
ExactNumber.gcd(),ExactNumber.lcm() - Minimum, maximum:
ExactNumber.min(),ExactNumber.max() - Parsing numbers in different bases:
ExactNumber.fromBase() - Range generator:
ExactNumber.range()
Rounding modes
NEAREST_TO_POSITIVE- Rounds to nearest number, with ties rounded towards +Infinity. Similar to Math.round().NEAREST_TO_NEGATIVE- Rounds to nearest number, with ties rounded towards -Infinity.NEAREST_TO_EVEN- Rounds to nearest number, with ties rounded towards the nearest even number.NEAREST_TO_ZERO- Rounds to nearest number, with ties rounded towards zero.NEAREST_AWAY_FROM_ZERO- Rounds to nearest number, with ties rounded away from zero.TO_POSITIVE- Rounds towards +Infinity. Similar to Math.ceil().TO_NEGATIVE- Rounds towards -Infinity. Similar to Math.floor().TO_ZERO- Rounds towards zero. Similar to Math.trunc().AWAY_FROM_ZERO- Rounds away from zero
Modulo variants
TRUNCATEDFLOOREDEUCLIDEAN
Read more about them here.
Approximation algorithms
These functions approximate irrational numbers with arbitrary number of decimals. The last parameter is always used to specify the number of correct decimals in the result.
- Roots:
sqrt(),cbrt(),nthroot() - Exponentials:
pow(),exp() - Logarithms:
log(),logn(),log10(),log2(), - Constants:
PI() - Trigonometric functions:
sin(),cos(),tan() - Inverse trigonometric functions:
asin(),acos(),atan() - Hyperbolic functions:
sinh(),cosh(),tanh() - Inverse hyperbolic functions:
asinh(),acosh(),atanh()
Copyright
License: MIT
Copyright © 2022 Dani Biró