#!/usr/bin/env ruby

require './Sinus'
require 'benchmark'

def simpson(x0, x1, n2)

	dx = (x1 - x0) / n2

	sum = 0
	(0..(n2/2)-1).each { |i|
		sum = sum + Math.sin(x0 + 2*i*dx) + 2*Math.sin(x0 + (2*i + 1)*dx)
	}

	(dx/3) * (Math.sin(x1) - Math.sin(x0) + 2*sum)
end

puts ""
[10, 100, 1000, 10000, 100000, 1000000].each { |n2|

	puts "-------------------------------------------------------"
	puts n2
	puts "-------------------------------------------------------"

	int1 = 0
	int2 = 0
	Benchmark.bm(9) do |b|
		b.report("Ruby    :") { int1 = simpson(0.0, Math::PI/2, n2) }
		puts "Ergebnis:  #{int1}"
		puts "Fehler  :  #{(1 - int1).abs}"
		puts ""
		b.report("C       :") { int2 = Sinus::simpson(0.0, Math::PI/2, n2) }
		puts "Ergebnis:  #{int2}"
		puts "Fehler  :  #{(1 - int2).abs}"
		puts ""
	end
}