emerging as low vol when compared to sp500

emerging as low vol when compared to sp500.r

require(quantmod)
require(PerformanceAnalytics)

getSymbols("VEIEX",from = "1900-01-01")  #use VEIEX Vanguard Emerging as proxy for emerging mkt stocks
getSymbols("VFINX",from = "1900-01-01") #use VFINX Vanguard SP500 as proxy for SP500

#get 1 day change for the emerging and sp500
roc <- na.omit(merge(ROC(VEIEX[,6],type="discrete",n=1),ROC(VFINX[,6],type="discrete",n=1)))
stdev <- rollapplyr(roc,FUN=sd,width=50)
#get relative strength of emerging versus S&P 500
rs <- VEIEX[,6]/VFINX[,6]

#do some trial graphs to see the interaction
plot.zoo(merge(stdev[,1]-stdev[,2],rs))
plot.zoo(merge(stdev[,1]-stdev[,2]/rs,rs))
plot.zoo(merge(stdev[,1]/stdev[,2],rs,VEIEX[,6]))

#create a PerformanceAnalytics rolling summary of emerging versus the S&P 500
charts.RollingRegression(roc[,1],roc[,2],width=250,main="")
title(main="Vanguard Emerging compared to the Vanguard S&P 500 (Rolling 1 Year)",outer=TRUE, line=-1.5, adj=0.05, cex.main=0.85)

#use colors provided in xblocks documentation
rgb <- hcl(c(0, 0, 260), c = c(100, 0, 100), l = c(50, 90, 50), alpha = 0.2)
plot.zoo(VEIEX[,6],    #plot closing price of emerging
         bty="n",    #no box; will fill in later with abline
         las=1,       #no rotation on y axis labels
         xlab = NA,
         ylab = NA)
xblocks(index(VEIEX[,6]), as.vector(stdev[,1]-stdev[,2]/rs > - 0.075),col = rgb[3])  #admittedly the -0.075 is ex-post
#connect the axes
abline(h=par("usr")[3])   #extend y axis
abline(v=par("usr")[1])   #extend x axis
abline(h=pretty(par("yaxp")),lty=1,lwd=2,col="white")  #try something new for gridlines
title(main="Vanguard Emerging VEIEX (source: Yahoo! Finance)",outer=TRUE, line=-2, adj=0.05)
mtext("blocks denote periods where Emerging 50 day sd low compared to S&P 500 sd",side=3,adj=0.05,cex=0.7,font=3, line=-1.5)