Math

The Math module adds many useful functions that extend Elixir's standard library.

• General Functions

  • a <~> b Comparison of floats, to check if they are effectively equal (if their absolute difference is less than @epsilon).
  • Math.pow(x, n) Arithmetic exponentiation. Works both with integer powers and floats.
  • Math.sqrt(x) The square root of x.
  • Math.nth_root(x, n) The n-th root of x.
  • Math.isqrt(x) The integer square root of x.
  • Math.gcd(a, b) The greatest common divisor of a and b.
  • Math.egcd(a, b) Calculates integers gcd, s, and t in as + bt = gcd(a,b). See also Math.gcd(a, b)
  • Math.lcm(a, b) The least common multiple of a and b.
  • Math.factorial(n) The n-th factorial number.
  • Math.k_permutations(n, k) The number of distinct ways to create groups of size k from n distinct elements.
  • Math.k_combinations(n, k) The number of distinct ways to create groups of size k from n distinct elements where order does not matter.
  • Math.mod_inv(a, m) An integer b that fufills ab = 1 (mod m). Returns an ok/error tuple.
  • Math.mod_inv!(a, m) See Math.mod_inv(a, m), but returns the value or raises an error.

• Logarithms

  • Math.exp(x) Calculates ℯ to the xth power.
  • Math.log(x) Calculates the natural logarithm (base ℯ) of x.
  • Math.log(x, b) Calculates the base-b logarithm of x
  • Math.log2(x) Calculates the binary logarithm (base 2) of x.
  • Math.log10(x) Calculates the common logarithm (base 10) of x.
  • Math.e Returns a floating-point approximation of the number ℯ.

• Trigonometry

  • Math.pi Returns a floating-point approximation of the number π.
  • Math.deg2rad(x) converts from degrees to radians.
  • Math.rad2deg(x) converts from radians to degrees.
  • Math.sin(x) The sine of x.
  • Math.cos(x) The cosine of x.
  • Math.tan(x) The tangent of x.
  • Math.asin(x) The inverse sine of x.
  • Math.acos(x) The inverse cosine of x.
  • Math.atan(x) The inverse tangent of x.
  • Math.atan2(x, y) The inverse tangent of x and y. This variant returns the inverse tangent in the correct quadrant, as the signs of both x and y are known.
  • Math.sinh(x) The hyperbolic sine of x.
  • Math.cosh(x) The hyperbolic cosine of x.
  • Math.tanh(x) The hyperbolic tangent of x.
  • Math.asinh(x) The inverse hyperbolic sine of x.
  • Math.acosh(x) The inverse hyperbolic cosine of x.
  • Math.atanh(x) The inverse hyperbolic tangent of x.

• Working with Collections

  • Math.Enum.product(collection) The result of multiplying all elements in the passed collection.
  • Math.Enum.mean(collection) the mean of the numbers in the collection.
  • Math.Enum.median(collection) the median of the numbers in the collection.
  • Math.Enum.mode(collection) the mode of the numbers in the collection.
  • Math.Enum.variance(collection) variance of the numbers in the collection.
  • Math.Enum.stdev(collection) the standard deviation of the numbers in the collection.

Installation

Math is available in Hex. The package can be installed by:

1. Add math to your list of dependencies in mix.exs:

def deps do
  [
    {:math, "~> 0.6.0"}
  ]
end

1. Require or import the Math library anywhere in your code you'd like:

require Math

# or

import Math

(Importing allows usage of the <~> operator)

Changelog

• 0.6.0 Adds Math.Enum.variance/1 and Math.Enum.stdev/1. Thank you, @TenTakano !
• 0.5.0 Adds Math.mod_inv, Math.mod_inv! and Math.egcd
• 0.4.0 Adds Math.Enum.mode/1.
• 0.3.1 Updates formatting to hide warnings in newer versions of Elixir.
• 0.3.0 Fixed incorrect median for lists with even number of items. Updated tests.
• 0.2.0 Added factorial/1, nth_sqrt/2, k_permutations/2, k_combinations/2, gcd/2, lcm/2 and Math.Enum functions. Improved documentation.
• 0.1.0 Added integer variant of pow/1, isqrt/2, deg2rad/1, rad2deg/1. Improved documentation.
• 0.0.1 First implementation, mostly a wrapper around Erlang's :math library.