I've searched the site but haven't found an easy way to backtest my personal portfolio allocations. Suppose I want to know the total return for the following portfolio from Jan 1, 2009 to Dec 31, 2014:
25% VINIX 25% VSMAX 25% VTMGX 25% VTRIX
I'm interested in total returns (distributions reinvested). It would be useful to model rebalancing strategies based on time (i.e. yearly) or by percentage drift from allocation. I'm agnostic as to programming language (python, R, ruby, etc.) but am looking for a basic library to test returns under a variety of such assumptions, ideally with good documentation/examples.