#####   R-code for making Figure 2.2

	postscript("fig22.ps",width=7,height=7,horizontal=F)

	par(mfrow=c(2,2), mar=c(4,4,1,1))

	x  <- seq(1,80)/10
	y1 <- (1/sqrt(2*pi))*x^(-0.5)*exp(-x/2)
	y2 <- (1/2)*exp(-x/2)
	y3 <- (1/2^1.5/(0.5*sqrt(pi)))*x^(0.5)*exp(-x/2)
	y4 <- (1/4)*x^(1)*exp(-x/2)

	plot(x,y1,type="l",xlab="x",ylab="f(x)",xaxt="n",yaxt="n",
	     ylim=c(0,1),mgp=c(2,1,0),cex=1)
	lines(x,y2,lty=2,cex=1)
	lines(x,y3,lty=3,cex=1)
	lines(x,y4,lty=4,cex=1)
	axis(1,at=c(0,2,4,6,8),labels=c("0","2","4","6","8"),cex=1)
	axis(2,at=c(0,0.25,0.5,0.75,1),labels=c("0","0.25","0.5","0.75","1"),
	     cex=1)
	legend(6,1,legend=c("k=1","k=2","k=3","k=4"),lty=1:4,cex=0.8)
	title(xlab="(a)")
	

	x  <- (seq(1,100)-50)/20
	y1 <- (1/sqrt(2*pi))*exp(-x^2/2)
	y2 <- (1/pi)*(1+x^2)^(-1)
	y3 <- (0.5/2)*(1+x^2/2)^(-1.5)
	y4 <- (2/(0.75*sqrt(5)*pi))*(1+x^2/5)^(-3)
	
	plot(x,y1,type="l",xlab="x",ylab="f(x)",xaxt="n",yaxt="n",
	     ylim=c(0,0.4),mgp=c(2,1,0),cex=1)
	lines(x,y2,lty=2,cex=1)
	lines(x,y3,lty=3,cex=1)
	lines(x,y4,lty=4,cex=1)
	axis(1,at=c(-2,-1,0,1,2),labels=c("-2","-1","0","1","2"),cex=1)
	axis(2,at=c(0,0.1,0.2,0.3,0.4),labels=c("0","0.1","0.2","0.3","0.4"),
	     cex=1)
	legend(1.02,0.4,legend=c("N(0,1)","t_1","t_2","t_5"),lty=1:4,cex=0.8)
	title(xlab="(b)")


	x  <- seq(1,80)/20
	y1 <- (3/(x+3))^4
	y2 <- 30*x^2/(x+1)^6
	y3 <- 8/(x*pi)*sqrt((3*x)^3*5^5/(3*x+5)^8)
	y4 <- 19*17*20*13*11/x*(x/(x+1))^10/(x+1)^10
	
	plot(x,y1,type="l",xlab="x",ylab="f(x)",xaxt="n",yaxt="n",
	     ylim=c(0,1.02),mgp=c(2,1,0),cex=1)
	lines(x,y2,lty=2,cex=1)
	lines(x,y3,lty=3,cex=1)
	lines(x,y4,lty=4,cex=1)
	axis(1,at=c(0,1,2,3,4),labels=c("0","1","2","3","4"),cex=1)
	axis(2,at=c(0,0.25,0.5,0.75,1),labels=c("0","0.25","0.5",
             "0.75","1"),cex=1)
	legend(2.66,1.02,legend=c("F_2,6","F_6,6","F_3,5","F_20,20"),
             lty=1:4,cex=0.8)
	title(xlab="(c)")


	x  <- seq(1,100)/40
	y1 <- 0.5*x^(-0.5)*exp(-x^0.5)
	y2 <- exp(-x)
	y3 <- 1.5*x^(0.5)*exp(-x^1.5)
	y4 <- 5*x^4*exp(-x^5)
	
	plot(x,y1,type="l",xlab="x",ylab="f(x)",xaxt="n",yaxt="n",
	     ylim=c(0,2.5),mgp=c(2,1,0),cex=1)
	lines(x,y2,lty=2,cex=1)
	lines(x,y3,lty=3,cex=1)
	lines(x,y4,lty=4,cex=1)
	axis(1,at=c(0,0.5,1,1.5,2,2.5),labels=c("0","0.5","1","1.5",
             "2","2.5"),cex=1)
	axis(2,at=c(0,0.5,1,1.5,2,2.5),labels=c("0","0.5","1","1.5",
             "2","2.5"),cex=1)
	legend(1.79,2.5,legend=c("b=0.5","b=1","b=1.5","b=5"),
             lty=1:4,cex=0.8)
	title(xlab="(d)")
	

	graphics.off()