module

Math

The Math module contains module functions for basic trigonometric and transcendental functions. See class Float for a list of constants that define Ruby’s floating point accuracy.

Domains and codomains are given only for real (not complex) numbers.


When mathn is required, the Math module changes as follows:

Standard Math module behaviour:

Math.sqrt(4/9)     # => 0.0
Math.sqrt(4.0/9.0) # => 0.666666666666667
Math.sqrt(- 4/9)   # => Errno::EDOM: Numerical argument out of domain - sqrt

After require ‘mathn’, this is changed to:

require 'mathn'
Math.sqrt(4/9)      # => 2/3
Math.sqrt(4.0/9.0)  # => 0.666666666666667
Math.sqrt(- 4/9)    # => Complex(0, 2/3)

Constants

E = DBL2NUM(M_E)

PI = DBL2NUM(M_PI)

Files

  • lib/mathn.rb
  • math.c

1Note

Input for trigonometric functions must be radians

emime · Mar 31, 2009

You must use radians to have the right result. For example to compute the sin of 125 degrees use:

Math.sin(125*Math::PI/180)