統計学
> x=seq(-5,5,length=500)
> i=c(0.5,1.0,1.5)
> y<-sapply(i,function(a){dnorm(x,mean=a,sd=1)})
> matplot(x,y,type="l",lty=1,col=1:3,ylab="density")
> legend(-4,0.4,paste("mean=",i,"sd=",1,sep=""),col=1:3,lty=1,bty="n")
> abline(h=0,v=0,lty=3)
CENTER: