There are a lot of code in Eric Zivots recent class in computational finance.
- http://spark-public.s3.amazonaws.com/compfinance/R%20code/portfolio.r
- http://spark-public.s3.amazonaws.com/compfinance/R%20code/testport.r
- http://spark-public.s3.amazonaws.com/compfinance/R%20code/rollingPortfolios.r
Also, you can google some slides in his class where he provides a lot of examples:
http://spark-public.s3.amazonaws.com/compfinance/Lecture%20Notes/PortfolioTheoryMatrixPowerpoint.pdf
Sample Code:
Standard Deviation of Return series:
sd(x) #where x = portfolio return series
Rolling Analysis
rollapplyr(x,days,function) #rolling analysis given function
Calculate Return
require(PerformanceAnalytics) #heaps of functions for portfolio analytics
require(TTR) #package with indicator functions
ROC(x,days) #given equity series, get log return
ROC(x,days,type="discrete") #given equity series, get discrete return series
findDrawdowns(R) #find drawdown for time series
Return.annualized(R,n) #R = return series, N = number of periods in year