Resemble velocity stepping tests more closely

src/one-body-sample.py

@@ -17,9 +17,9 @@ class dirichletCondition:
         fst = 3e-4
         snd = 5e-4
         trd = 3e-4
-        if x < 1.0/3:
+        if x < 1.0/5:
             return fst
-        elif x < 2.0/3:
+        elif x < 3.0/5:
             return snd
         else:
             return trd