big-rational
An arbitrary length rational number library for Javascript
npm install big-rational
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Version | 0.9.3 last updated a year ago |
License | WTFPL |
Keywords | math, big, bignum, bignumber, bigrational, rational, arbitrary, precision, arithmetic |
Repository | git@github.com:peterolson/BigRational.js.git (git) |
Dependencies | big-integer |
BigRational.js
BigRational.js is an arbitrary-length rational number library for Javascript, allowing arithmetic operations on rational numbers of unlimited size, notwithstanding memory and time limitations.
A rational number is stored internally as a pair of two big integers. Because of this, BigRational.js depends on my big integer library, BigInteger.js.
Installation
If you are using a browser, you can download BigRational.js from GitHub or just hotlink to it.
<script src="http://peterolson.github.com/BigRational.js/BigInt_BigRat.min.js"></script>
This will include both the bigInt
library and the bigRat
library. If you want to reference them separately, you can use the non-combined BigRational.js script.
If you are using node, you can install BigRational.js with npm.
npm install big-rational
Then you can include it in your code
var bigRat = require("big-rational");
bigRat(num?, denom?)
You can create a bigRational by calling the bigRat
function. You can pass in up to two paramers.
bigRat()
If you pass in zero parameters, it will return zero.
bigRat(n)
If you pass in one parameter, it must be one of the following:
- a string, which may be
- an integer, such as
"12345"
, - a numerator over a denominator, such as
"2/3"
, - a mixed fraction, such as
"1_1/2"
- a decimal number, such as
"54.05446"
- an integer, such as
- a Javascript number
- a bigInteger
- a bigRational
bigRat(num, denom)
If you pass in two parameters, the first will be interpreted as the numerator, and the second as the denominator. Both parameters must be one of the following:
- a string in integer form, such as
"12345"
- a JavaScript number that is an integer, such as
12345
- a bigInteger
Examples:
var zero = bigRat();
var threeFourths = bigRat("3/4") ||
bigRat("3", "4") ||
bigRat(3, 4) ||
bigRat(3 / 4) ||
bigRat(0.75);
var fiveHalves = bigRat("5/2") ||
bigRat("2_1/2");
Method Chaining
Note that bigRat operations return bigRats, which allows you to chain methods, for example:
var salary = bigRat(dollarsPerHour).times(hoursWorked).plus(randomBonuses)
Constants
There are three constants already stored that you do not have to construct with the bigRat
function yourself:
bigRat.one
, equivalent tobigRat(1)
bigRat.zero
, equivalent tobigRat(0)
bigRat.minusOne
, equivalent tobigRat(-1)
Properties
You can obtain the numerator and denominator of a bigRational with these properties:
numerator
Returns the numerator of a bigRational. This will be a bigInt.
bigRat(34, 3).numerator
=>bigInt(34)
denominator
Returns the denominator of a bigRational. This will be a bigIn.t
bigRat(34, 3).denominator
=>bigInt(3)
num
Alias for the numerator
property
denom
Alias for the denominator
property
Methods
abs
Returns the absolute value of a number.
bigRat(-424).abs().equals(424)
add
Performs addition.
bigRat("1/3").add(1, 3).equals(2, 3)
ceil(toBigInt?)
Rounds up to the nearest integer. If the toBigInt
argument is true
, then it will return a bigInteger instead of a bigRational.
bigRat(12345.4).ceil().equals(12346)
compare
Performs a comparison between two numbers. If the numbers are equal, it returns 0
. If the first number is greater, it returns 1
. If the first number is lesser, it returns -1
.
bigRat(3).compare(3) === 0
bigRat(3).compare(4) === -1
bigRat(4).compare(3) === 1
divide
Performs division.
bigRat("354.25").divide(1, 4).equals(1417)
equals
Checks if two numbers are equal.
bigRat(1).equals(1)
floor(toBigInt?)
Rounds down to the nearest integer. If the toBigInt
argument is true
, then it will return a bigInteger instead of a bigRational.
bigRat(987.99999).floor().equals(987)
greater
Checks if the first number is greater than the second
bigRat(5).greater(4)
greaterOrEquals
Checks if the first number is greater than or equal to the second
bigRat(5).greaterOrEquals(5)
bigRat(5).greaterOrEquals(4)
isNegative
Returns true
if the number is negative, false
otherwise.
bigRat(-7).isNegative()
isPositive
Returns true
if the number is positive, false
otherwise.
bigRat(7).isPositive()
isZero
Returns true
if the number equals 0, false
otherwise.
bigRat(0).isZero()
lesser
Checks if the first number is lesser than the second
bigRat(4).lesser(5)
lesserOrEquals
Checks if the first number is lesser than or equal to the second
bigRat(4).lesserOrEquals(4)
bigRat(4).lesserOrEquals(5)
minus
Alias for subtract
.
mod
Performs the modulo operation.
bigRat(3).mod(2).equals(1)
multiply
Performs multiplication.
bigRat(70, 2).multiply(4).equals(140)
negate
Returns the negation of a number.
bigRat(234).negate().equals(-234)
notEquals
Checks if two numbers are not equal.
bigRat(1).notEquals(2)
over
Alias for divide
.
plus
Alias for add
.
round(toBigInt?)
Rounds a number to the nearest integer. If the number is exactly half-way between two integers, it will round up.
If the toBigInt
argument is true
, then it will return a bigInteger instead of a bigRational.
- bigRat(54345.12566).round().equals(54345)
- bigRat(1234567.5).round().equals(1234568)
- bigRat(69.8).round().equals(70)
subtract
Performs subtraction.
- `bigRat(3).subtract(2).equals(1)
times
Alias for multiply
.
toDecimal(digits?)
Converts a bigRational to a string in decimal notation, cut off after the number of digits specified in the digits
argument. The default number of digits is 10.
bigRat(1,3).toDecimal() === "0.33333333333"
bigRat(1,7).toDecimal(14) === "0.142857142857143"
Override Methods
toString()
Converts a bigRat to a string in "numerator/denominator" notation.
bigRat(145.545).toString() === "29109/200"
valueOf()
Converts a bigRat to a native Javascript number. This override allows you to use native arithmetic operators without explicit conversion:
bigRat(1, 4) + bigRat(3, 4) === 1