1 //val urban_deltas = get_deltas(get_prices(List("GOOG", "AAPL"), 2010 to 2012))

     2 

     3 val ds_urban = List(List(Some(-0.03573992567129673), Some(0.539975124774038)), 

     4                     List(Some(0.10103412653643493), Some(0.24777709700099845)))

     5 

     6 

     7 

     8 assert(yearly_yield(ds_urban, 100, 0) == 125)

     9 assert(yearly_yield(ds_urban, 100, 1) == 117)