Second Order Recurrence Relations

SORR.rb

# PROJECT: Second Order Recurrence Relations
$LOAD_PATH << '../lib'
require 'parseFile.rb'

class Sorr
  
  def initialize(inputs)
    s1 = inputs["S(1)"];  s2 = inputs["S(2)"]
    c1 = inputs['C1'];    c2 = inputs['C2']
    r1,r2 = quadratic(c1,c2)
    
    puts "r1 = #{r1}"
    puts "r2 = #{r2}"
    
    unless r1 == r2  
      q = ((s2 - (s1 * r1) ) / ( ( -r1 ) + r2 ))
      p = s1 - q
      puts "p = #{p}"
      puts "q = #{q}"
      puts "S(n) = (#{p})(#{r1})^(n-1) + (#{q})(#{r2})^(n-1)"
      for i in 1..10 do
        puts "S(#{i}) = #{(p*r1**(i-1) + q*r2**(i-1))}"  
      end      
    else
      p = s1
      q = ( s2 - p*r1 ) / r1
      puts "p = #{p}"
      puts "q = #{q}"
      puts "S(n) = #{r1}^(n-1) + #{q}(n-1)*#{r1}^(n-1)"
      for i in 1..10 do
        puts "S(#{i}) = #{r1**(i-1) + q*(i-1)*r1**(i-1)}"
      end
    end #unless
  end #initialize
  
  def quadratic(b,c)
     [ ( b + Math.sqrt(b**2 + 4 * c) ) / 2,
     ( b - Math.sqrt(b**2 + 4 * c) ) / 2 ]   
  end #quadratic
end #class Sorr

begin
  parsed = Master::ParseFile.new(Hash)
  if parsed.getFile.instance_of?(Hash) then Sorr.new(parsed.getFile) end
end