val urban_prices = List(List(Some(311.349976), Some(27.505054)), 
			List(Some(300.222351), Some(42.357094)), 
			List(Some(330.555054), Some(52.852215)))


assert(CW6c.yearly_yield(CW6c.get_deltas(urban_prices), 100, 0) == 125)


val urban_blchip_portfolio = List("GOOG", "AAPL", "MSFT", "IBM", "FB", "AMZN", "BIDU")
val urban_rstate_portfolio = List("PLD", "PSA", "AMT", "AIV", "AVB", "BXP", "CCI", 
                                  "DLR", "EQIX", "EQR", "ESS", "EXR", "FRT", "GGP", "HCP") 


assert(CW6c.investment(urban_rstate_portfolio, 1978 to 2017, 100) == 30839)
assert(CW6c.investment(urban_blchip_portfolio, 1978 to 2017, 100) == 349597)