Commodity Index Estimators

In this post I will show my first try at a commodity index substitute.  Regular readers know my frustration with proprietary data as I try to demonstrate various techniques to users who might not have the resources to pay for the data.  I have substituted US 10y Treasury Total Returns series as my bond proxy with good results, but I have so far been unable to find a free and readily available substitute for commodity indexes.
PPI is not real-time, but might offer one good 1-month lagged proxy for commodity indexes.  If we use PPI data from the St. Louis Federal Reserve FRED system, I can get close, but I am unsure if it will be close enough until further system testing.

From TimelyPortfolio

From TimelyPortfolio

From TimelyPortfolio

From TimelyPortfolio

R code:
require(PerformanceAnalytics)
require(quantmod)
#getSymbols("NAPMPRI",src="FRED") #load ISM Manufacturing Price
getSymbols("PPIACO",src="FRED") #load PPI All Commodities
getSymbols("PPICRM",src="FRED") #load PPI Crude for Further Processing
getSymbols("PPIIDC",src="FRED") #load PPI Industrial
#unfortunately cannot get substitute for proprietary CRB data
#get data series from csv file
CRB<-as.xts(read.csv("spxcrbndrbond.csv",row.names=1))[,2]
#my CRB data is end of month; could change but more fun to do in R
CRB<-to.monthly(CRB)[,4]
index(CRB)<-as.Date(index(CRB))
#NAPMPRI_change<-ROC(NAPMPRI,1)
PPIACO_change<-ROC(PPIACO,1)
PPICRM_change<-ROC(PPICRM,1)
PPIIDC_change<-ROC(PPIIDC,1)
#combine all Rate of Change series with CRB lag 1 month (moved forward) to account for PPI delay
CRBandPPI<-merge(lag(CRB,k=1),PPIACO_change,PPICRM_change,PPIIDC_change)
colnames(CRBandPPI)<-c("CRB","PPI All Comm","PPI Crude for Further","PPI Industrial")
chart.CumReturns(CRBandPPI,main="CRB Estimators through PPI",legend.loc="topleft")
chart.CumReturns(CRBandPPI["1990::"],main="CRB Estimators through PPI since 1990",legend.loc="topleft")
chart.Correlation(CRBandPPI,main="CRB Estimators through PPI")
chart.Correlation(CRBandPPI["1990::"],main="CRB Estimators through PPI since 1990")