--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main_marking1/drumb_test5.scala	Fri Jan 22 10:37:55 2021 +0000
@@ -0,0 +1,27 @@
+/*def myassert(cond : => Boolean) = {
+  try {
+    assert(cond)
+  } catch { 
+    case _ : Throwable => System.exit(1)
+  }
+}
+*/
+// get_prices(List("GOOG", "AAPL"), 2010 to 2012)
+val urban_prices = List(List(Some(312.204773), Some(26.782711)), 
+                        List(Some(301.0466), Some(41.244694)), 
+                        List(Some(331.462585), Some(51.464207)))
+
+
+assert(CW6b.get_deltas(urban_prices) == List(List(Some(-0.03573991804411003), Some(0.539974575389325)), 
+                                          List(Some(0.10103414222249969), Some(0.24777764141006836))))
+
+
+//get_prices(List("BIDU"), 2004 to 2008)
+val urban_prices2 = List(List(None), List(None), 
+                         List(Some(6.35)), List(Some(12.241)), 
+                         List(Some(38.188)))
+
+
+assert(CW6b.get_deltas(urban_prices2) == List(List(None), List(None), 
+                                        List(Some(0.9277165354330709)), 
+                                        List(Some(2.119679764725104))))