Research Article

Model Selection Approaches for Predicting Future Order Statistics from Type II Censored Data

Algorithm 1

R code of Example 1.
rextreme=function(n,mu,sig)mu+sig(log(-log(1-runif(n))))
dextreme=function(x,mu,sig)(1/sig)exp((x-mu)/sig-exp((x-mu)/sig))
pextreme=function(x,mu,sig)1-exp(-exp((x-mu)/sig))
n=13
r=10
data=log(c(0.22, 0.50, 0.88, 1.00, 1.32, 1.33, 1.54, 1.76, 2.50, 3.00))
data1=sort(data)[1:r]
Xr=data1[r]
# AMLE of normal
   pr=r/(n+1)
   qr=1-pr
   invpr=qnorm(pr,0,1)
   alpha=dnorm(invpr)((1+invpr2)qr-invprdnorm(invpr))/(qr2)
   beta=dnorm(invpr)(dnorm(invpr)-invprqr)/(qr2)
   A=sum(data1)+beta(n-r)Xr
   M=r+beta(n-r)
   C=(n-r)alpha
   D=AC/M-CXr
   E=sum(data12)+(n-r)beta(Xr2)-A2/M
   sigma_hat=(-D+(D2+4rE)(1/2))/(2r)
   u_hat=A/M+Csigma_hat/M
## MLE of normal
L2=function(x)
   u=x[]
   sigma=x[]
   -(prod(dnorm(data1,u,sigma))(1-pnorm(Xr,u,sigma))(n-r))
  Ans1=optim(c(u_hat,sigma_hat),L2)
  uN=Ans1$par[]
  sigmaN=Ans1$par[]
## AMLE of extreme value
  prE=r/(n+1)
  qrE=1-prE
  alphar=1+log(qrE)-log(qrE)log(-log(qrE))
  betar=-log(qrE)
  SUMbeta=SUMbetaX=SUMalpha=SUMalphaX=SUMbetaX2=0
  for(h in 1:r)
  pi=h/(n+1)
  qi=1-pi
  alphai=1+log(qi)-log(qi)log(-log(qi))
  betai=-log(qi)
  SUMbeta=SUMbeta+betai
  SUMbetaX=SUMbetaX+betaidata1[h]
  SUMalpha=SUMalpha+alphai
  SUMalphaX=SUMalphaX+alphaidata1[h]
  SUMbetaX2=SUMbetaX2+betai((data1[h])2)
  M=SUMbeta+betar(n-r)
  B=(SUMbetaX+(n-r)betarXr)/M
  C=(SUMalpha-(n-r)(1-alphar))/M
  D=-(n-r)Xr+(n-r)alpharXr+SUMalphaX-BCM
  E=(n-r)betar(Xr2)+SUMbetaX2-M(B2)
  sigma_hat=(-D+(D2+4rE)(1/2))/(2r)
  u_hat=B-Csigma_hat
## MLE of extreme value
L9=function(x)
   u=x[]
   sigma=x[]
   -(prod(dextreme(data1,u,sigma))(1-pextreme(Xr,u,sigma))(n-r))
  Ans9=optim(c(u_hat,sigma_hat),L9)
  uE=Ans9$par[]
  sigmaE=Ans9$par[]
## Model Selection Approaches
 Dsp1=Dsp2=D1=D2=array()
 for(j in 1:r)
L7=factorial(n)/(factorial(n-r))
LN=L7prod(dnorm(data1,uN,sigmaN))(1-pnorm(Xr,uN,sigmaN))(n-r)
LE=L7prod(dextreme(data1,uE,sigmaE))(1-pextreme(Xr,uE,sigmaE))(n-r)
Dsp1[j]=(2/pi)abs(asin(sqrt((j-0.5)/n))-asin(sqrt(pnorm(data1[j],uN,sigmaN))))
Dsp2[j]=(2/pi)abs(asin(sqrt((j-0.5)/n))-asin(sqrt(pextreme(data1[j],uE,sigmaE))))
D1[j]=(2/pi)abs(((j-0.5)/n)-pnorm(data1[j],uN,sigmaN))+0.5/n
D2[j]=(2/pi)abs(((j-0.5)/n)-pextreme(data1[j],uE,sigmaE))+0.5/n
DspN=max(Dsp1)
DspE=max(Dsp2)
#DN=max(D1)
#DE=max(D2)
## The Taylor series prediction
AMLP_E=function(r,n)
 pr=r/(n+1)
 qr=1-pr
 Xs2=array()
for(i in 1:(n-r))
s=r+i
 ps=s/(n+1)
qs=1-ps
 alphas=1+log(qs)-log(qs)log(-log(qs))
 betas=log(qs)
gamma1=qslog(qs)((qr-qs)(-1+(1+log(qs))log(-log(qs)))+qslog(qs)log(-log(qs))-
  qrlog(qr)log(-log(qr)))/((qr-qs)2)
rou1=qslog(qs)(-(1+log(qs))(qr-qs)-qslog(qs))/((qr-qs)2)
  v1=qslog(qs)qrlog(qr)/((qr-qs)2)
  A=s-r-1
  B=Arou1+Av1+betas+(n-s)betas
  C=Agamma1+alphas-(n-s)+(n-s)alphas
  D=Arou1+betas+(n-s)betas
  Xs2[i]=-Av1data1[r]/D+uEB/D-sigmaEC/D
  Xs2[which(Xs2<=data1[r])]=data1[r]
 Xs2
AMLP_E(r,n)