# R code for the figures for lecture 6 require(np) require(lattice) data(oecdpanel) ############################# Figure 1 ############################ # Fit the joint density of logarithmic population growth and investment # rates popinv <- npudens(~popgro+inv, data=oecdpanel) # Call the np plotting routine, but just ask it to calculate, rather than to # make a plot --- see help(npplot) fhat <- plot(popinv,plot.behavior="data") # Extract the one joint density (since it could return multiple objects # together fhat <- fhat\$d1 # Now fhat\$eval contains the grid of evaluation points, and fhat\$dens the # actual density values # Make a contour plot of the joint density, with more levels, and smaller # labels on the levels, than usual contourplot(fhat\$dens~fhat\$eval\$Var1*fhat\$eval\$Var2,cuts=20,xlab="popgro", ylab="inv",labels=list(cex=0.5)) ############################# Figure 2 ############################ # Fit the density of logarithmic population growth rates conditional on year pop.cdens <- npcdens(popgro ~ year,data=oecdpanel) # Manually construct a grid of points on which to plot plotting.grid <- expand.grid(year=seq(from=1965,to=1995,by=1), popgro=seq(from=-3.5,to=-2.4,length.out=300)) # Evaluate the function fhat <- predict(pop.cdens,newdata=plotting.grid) # Make a wireframe plot wirefame(fhat~plotting.grid\$year*plotting.grid\$popgro,scales=list(arrows=FALSE), xlab="year",ylab="popgro",zlab="pdf") ############################ Figure 3 ############################## # Fit the density of popgro conditional on year and OECD membership pop.cdens.o <- npcdens(popgro~year+factor(oecd),data=oecdpanel) # Ensure that npcdens treats oecd as a categorical variable, not a number # Make the grid, but now include the OECD factor plotting.grid <- expand.grid(year=seq(from=1965,to=1995,by=1), popgro=seq(from=-3.4,to=-2.4,length.out=300), oecd=unique(oecdpanel\$oecd)) fhat <- predict(pop.cdens.o,newdata=plotting.grid) # Make side-by-side wireframes, conditional on OECD membership wireframe(fhat~plotting.grid\$year*plotting.grid\$popgro|plotting.grid\$oecd, scales=list(arrows=FALSE),xlab="year",ylab="popgro",zlab="pdf") ############################ Figure 4 ############################## # Code omitted --- reproducing the figure is a challenge exercise