# PLOTS IN LECTURE NOTES AND EXERCISES # ========================================================================================== # One proportion examples from CLAYTON & HILLS: # ============================================= # Likelihood #==================== x=c(1,1,0,1,0,0,0,1,0,0) m=mean(x) p=seq(m-0.3,m+0.3,0.01) L<-rep(0,length(p)) for (i in 1:length(p)) L[i]=prod(dbinom(x,1,p[i])) plot(p,L,type="l") abline(v=0.4) # Likelihood ratio (compared to most likely) #======================================== x=c(1,1,0,1,0,0,0,1,0,0) m=mean(x) p=seq(m-0.3,m+0.3,0.001) LR<-rep(0,length(p)) ml<-prod(dbinom(x,1,0.4)) for (i in 1:length(p)) LR[i]=prod(dbinom(x,1,p[i]))/ml plot(p,LR,type="l") abline(v=0.4,h=0.258) arrows(0.178,0.258,0.178,0) arrows(0.655,0.258,0.655,0) # Likelihood ratio for large sample size #======================================== x=rep(c(1,0),c(20,30)) m=mean(x) p=seq(m-0.3,m+0.3,0.001) LR<-rep(0,length(p)) ml<-prod(dbinom(x,1,0.4)) for (i in 1:length(p)) LR[i]=prod(dbinom(x,1,p[i]))/ml plot(p,LR,type="l") abline(v=0.4,h=0.258) arrows(0.291,0.258,0.291,0) arrows(0.516,0.258,0.516,0) # Log likelihood #================ x=c(1,1,0,1,0,0,0,1,0,0) m=mean(x) p=seq(m-0.3,m+0.3,0.01) l<-rep(0,length(p)) ml<-prod(dbinom(x,1,0.4)) for (i in 1:length(p)) l[i]=sum(log(dbinom(x,1,p[i])))-log(ml) plot(p,l,type="l",ylab="l") abline(v=0.4) abline(v=0.4,h=-1.353) arrows(0.178,-1.353,0.178,-3) arrows(0.655,-1.353,0.655,-3) # ========================================================================================== library(lattice) # Exercise 1 on binned data #==================== # 2-d version mu<-seq(-10,100,1) sigma=seq(0.1,10,0.5) g<-expand.grid(mu=mu,sigma=sigma) count<-0 for (i in 1:length(mu)) { for (j in 1:length(sigma)) { count<-count+1 g$L[count]<-(pnorm(4,mu[i],sigma[j])-pnorm(3,mu[i],sigma[j]))*(pnorm(6,mu[i],sigma[j])-pnorm(4,mu[i],sigma[j]))*(1-pnorm(5,mu[i],sigma[j]))*(pnorm(3.6,mu[i],sigma[j])) } } g[g$L==max(g$L),] wireframe(L~mu*sigma,data=g,drape = TRUE, colorkey = TRUE,scale=list(arrows=FALSE),abline=g[g$L==max(g$L),]) # tumbler mortality: #==================== # 2-d solution a<-read.table("x://teaching//bios602 (2009)//tumbler.txt",header=T) rate<-seq(0.01,0.3,0.01) shape<-seq(0.1,3,0.1) g<-expand.grid(shape=shape,rate=rate) count<-0 for (i in 1:length(shape)) { for (j in 1:length(rate)) { count<-count+1 p<-(pgamma(a$x,shape[i],rate[j])-pgamma(a$x-1,shape[i],rate[j]))/(1-pgamma(a$x-1,shape[i],rate[j])) g$L[count]<-sum(a$n*log(p)+(a$N-a$n)*log(1-p)) } } g[g$L==max(g$L),] wireframe(L~shape+rate,data=g,drape = TRUE, colorkey = TRUE,scale=list(arrows=FALSE),abline=g[g$L==max(g$L),])