array-math
v1.1.3
Published
Do math on arrays: find divisors or factors of a number, sum or multiply an array, and much more!
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array-math
modularity
Sorry, I built this before I learned the truth about modularity. See the following links for enlightenment. ;-)
- http://substack.net/finding_modules
- http://substack.net/how_I_write_modules
- http://substack.net/many_things
api
var aMath = require('array-math')
aMath.factors(n)
If you only want this function, try primefactors.
n
must be a positive integer
aMath.factors(2) // -> [2]
aMath.factors(96) // -> [2, 2, 2, 2, 2, 3]
aMath.factors(100) // -> [2, 2, 5, 5]
aMath.divisors(n[, opts])
If you only want this function, you could factor it out, and send me a PR with a link to your module! (Grab the test file while you're at it.)
n
must be a positive number.opts
is an object with the options. Defaults to{}
.proper
can be insideopts
. Iftrue
, it will make the resulting array not includen
. Defaults tofalse
.
aMath.divisors(2) // -> [2]
aMath.divisors(96) // -> [1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 96]
aMath.divisors(100) // -> [1, 2, 4, 5, 10, 20, 25, 50, 100]
aMath.divisors(100, {proper:true}) // -> [1, 2, 4, 5, 10, 20, 25, 50]
aMath.isPrime(n)
If you only want this function, try isprime.
n
must be a positive integer
aMath.isPrime(2) // -> true
aMath.isPrime(3) // -> true
aMath.isPrime(4) // -> false
aMath.isPrime(7) // -> true
aMath.isPrime(96) // -> false
aMath.isPrime(97) // -> true
aMath.isPrime(100) // -> false
aMath.isPrime(113) // -> true
aMath.isPrime(117) // -> false
aMath.range([start,] stop [,step])
If you only want this function, try array-range. (Does not have stepping built in.)
start
is the starting number of the range. Defaults to0
. If there are 2 or 3 arguments, this is assumed to be the first.stop
is the ending number of the range. Defaults to0
. If there is 1 argument, this is assumed to be it.step
is the step between each number. Defaults to1
. This is may not be0
, and is set to1
if it is.
aMath.range() // -> []
aMath.range(0) // -> []
aMath.range(1) // -> [0]
aMath.range(2) // -> [0, 1]
aMath.range(2, 2) // -> []
aMath.range(2, 3) // -> [2]
aMath.range(3) // -> [0, 1, 2]
aMath.range(10) // -> [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
aMath.range(2, 10) // -> [2, 3, 4, 5, 6, 7, 8, 9]
aMath.range(5, 10) // -> [5, 6, 7, 8, 9]
aMath.multiply(a)
If you only want this function, it might be best to just write it yourself:
arr.reduce(function (prdct, fctr) { return prdct * fctr }, 1)
a
must be an array of numbers (integers, floats, negative, whatever).
aMath.multiply([2, 96, 100]) // -> 19200
aMath.multiply([40, 3, 17]) // -> 2040
aMath.multiply([4, 5, 2, 5.2, 3.8]) // -> 790.4
aMath.multiply([520, 0.2, 0.2, 0.8]) // -> 16.64
aMath.sum(a)
If you only want this function, it might be best to just write it yourself:
arr.reduce(function (sum, val) { return sum + val }, 0)
a
must be an array of numbers (integers, floats, negative, whatever).
aMath.sum([2, 96, 100]) // -> 198
aMath.sum([2, -96, 100]) // -> 6
aMath.sum([45, 20, 8.3]) // -> 73.3
aMath.factorial(h[, l])
If you only want this function, try factorial. (Does not have low number built in.)
h
must be a number. It is the high number. It defaults to 0.l
must be a number. It is the low number. It defaults to 0.
While multiplying, it will never multiply by 0.
aMath.factorial() // -> 1
aMath.factorial(0) // -> 1
aMath.factorial(1) // -> 1
aMath.factorial(2) // -> 2 (2x1)
aMath.factorial(3) // -> 6 (3x2x1)
aMath.factorial(5) // -> 120 (5x4x3x2x1)
aMath.factorial(5, 0) // -> 120 (5x4x3x2x1)
aMath.factorial(5, 1) // -> 120 (5x4x3x2x1)
aMath.factorial(5, 2) // -> 120 (5x4x3x2)
aMath.factorial(5, 3) // -> 60 (5x4x3)
aMath.factorial(5, 4) // -> 20 (5x4)
aMath.factorial(10) // -> 3628800 (10x9x8x7x6x5x4x3x2x1)
aMath.factorial(10, 3) // -> 1814400 (10x9x8x7x6x5x4x3)
aMath.factorial(10, 5) // -> 151200 (10x9x8x7x6x5)
install
Install with NPM
npm install array-math