Contents

require_relative 'point.rb'

class Sphere

  attr_reader :radius, :center
  attr_accessor :pct_error

  def initialize(radius = 1, center = [0,0,0], pct_error = 1)
    @radius = radius
    @center = Point.new(center)
    @pct_error = pct_error
  end

  def self.help
    Sphere.show_help_message
  end

  def help
    Sphere.help
  end

  def on_sphere?(point)
    Zadt::Universe.distance(@center, point).round(2) == radius.round(2)
  end

  def in_sphere?(point)
    Zadt::Universe.distance(@center, point) <= @radius
  end

  def how_far_from_sphere(point)
    (@radius - Zadt::Universe.distance(@center, point)).abs
  end

  def volume
    dim_check(3)
    Math::PI * (@radius ** 3) * 4.0 / 3.0
  end

  def surface_area
    dim_check(3)
    4.0 * Math::PI * (@radius ** 2)
  end

  def equation
    dim_check(3)
    center_point = @center.dup
    coord_names = ["x", "y", "z"]
    center_point.coords.each_with_index do |center_coord, index|
      if center_coord == 0
        # coord_name is fine
      elsif center_coord < 0
        coord_names[index] = "(#{coord_names[index]} + #{-center_coord})"
      else
        coord_names[index] = "(#{coord_names[index]} - #{center_coord})"
      end
    end
    "#{coord_names[0]}^2 + #{coord_names[1]}^2 + #{coord_names[2]}^2 = #{@radius ** 2}"
  end

  def inspect
    "Sphere: #{equation}"
  end

  private

  def self.show_help_message
    Zadt::ADT::show_sphere_help_message
  end

  def close_enough(guess, exact)
    range = Array.new
    range[0] = exact *(100.0 - @pct_error)/100.0
    range[1] = exact * (100.0 + @pct_error)/100.0
    guess.between?(range[0], range[1])
  end

  def dim_check(num)
    raise "dimension error" unless num == @center.dims
  end

end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
zadt-1.1.0	lib/zadt/AbstractDataTypes/Geometrics/sphere.rb
zadt-0.1.9	lib/zadt/AbstractDataTypes/Geometrics/sphere.rb