Excel fvschedule function in Ruby

fvschedule.rb

def fvschedule(principal=1.0, schedule)
	total_return = principal
	schedule.each{|x| total_return*=(1+x)}
	return total_return
end

def annualized_return(period, schedule)
	ann_return = 0
	schedule_length = schedule.length
	if schedule_length/Float(period) > 1
		ann_return = (fvschedule(schedule))**(Float(period)/schedule_length) - 1
		return ann_return
	else
		ann_return = fvschedule(schedule) - 1
		return ann_return
	end
end

def test_fvschedule()
	returns = [0.05,0.03,-0.10,0.03,-0.04,0.20,-0.10,0.05,0.02,-0.04,0.04,0.15,0.03,-0.10,0.07]
	puts(fvschedule(returns))
	puts(annualized_return(12,returns))
end

Link to Microsoft documentation on FVSCHEDULE

1. fvschedule excel function in Ruby to calculate total compounding value of a return stream with principal.
2. annualized_return function to calculate the annualized return of a return stream, which returns the total return if number of periods is less than one year.