Ruby Math.radians

Question

I need Math.radians() function and cannot find it.

radians=(angle/180)* Math::PI

Answer 1

You probably want to create a file called "mymath.rb" in the lib/ directory, and monkey patch Math, like this:

require 'mathn'
module Math
  def self.to_rad angle
    angle / 180.0 * Math::PI
  end
end

---

or you can do what @MBO said in his comment. The link seems to be down, but the Google archives yield this informative little sentence, which indicates a solution that may be cleaner than mine (though I prefer keeping math stuff inside of math):

The simplest solution is to define a conversion method in Numeric that will convert a number of degrees into radians.

As a note, Ruby 2.0 has a feature called "Refinement" that basically lets you do local monkey-patching. It works this way (lifted from this blog post :

module RadiansConversion
  refine Math do
    def to_rad angle
      angle / 180.0 * Math::PI
    end
  end
end

And then .... It's available inside another module or anything such like that.

module MyApp
  using RadiansConversion

  p Math.to_rad 180   #=> 3.14159265358979
  p Math.to_rad 235   #=> 4.10152374218667
end