Friendly function for creating pool performance vector

[yellowbean]

Background

By current design, the CDR CPR vector curve is just a python list ,which is not easy way to understand how this vector being applied to pool performance .

Question _0.01 being applied to what asset periods ? when the 0.01 starts ? _

Solution 1: create a util function to create pool performance vector via dates

function buildVector():

buildVector( dealObject, "CDR",  ["<date1>",<val1>],[<date2>,<val2>].....)
# it will drop the data points before projection start date ( cutoff date / and previous collection date ) 
# if the <date1> is after the projection start date , raise error