我在winbugs中算了一个模型，现在想求它的残差，以此做ARCH-LM检验，求助ing

程序如下：
model{
for(t in 1:T){y[t]~dnorm(a[t],p[t])
LL[t]<--0.5*log(6.28)-0.5*log(h[t])-0.5*pow(y[t]-a[t],2)/h[t]}
h1~dgamma(2,100)
h2~dgamma(2,100)
h3~dgamma(2,100)
h[1]<-h1
h[2]<-h2
h[3]<-h3
p[1]<-1/h[1]
p[2]<-1/h[2]
p[3]<-1/h[3]
a1~dnorm(0,0.001)
a2~dnorm(0,0.001)
a3~dnorm(0,0.001)
a[1]<-a1
a[2]<-a2
a[3]<-a3
for(t in 4:T){h[t]<-lambda+alpha*pow(y[t-1]-a[t-1],2)+beta*h[t-1]
F[t-1]<-(1-exp(-gamma*pow(y[t-1]-r,2)))
a[t]<-A[1]+B[1]*y[t-1]+B[2]*y[t-2]+(A[2]+C[1]*y[t-1]+C[2]*y[t-2]+C[3]*y[t-3])*F[t-1]
p[t]<-1/h[t]}

lambda~dnorm(0,0.001)I(0,100)
alpha~dnorm(0,0.001)I(0,1)
beta~dnorm(0,0.001)I(0,1)
gamma~dnorm(1,0.001)I(1,10000)
r~dunif(-0.3,0.3)
for(k in 1:2){
A[k]~dnorm(0,0.001)
B[k]~dnorm(0,0.001)}
for(k in 1:3){
C[k]~dnorm(0,0.001)}
}


DATA

list(T=39, y=c(8.1056,         8.0998,         8.092,         8.0845,         8.0804,         8.0702,         8.0608,         8.0415,         8.017,         8.0165,         8.0188,         7.9956,         7.9732,         7.9585,         7.9087,         7.8792,         7.8436, 7.8087,         7.7776,         7.7409,         7.7342,         7.7139,         7.6506,         7.6155,         7.5737,         7.5607,         7.5108,         7.4692,         7.3997,         7.3046,         7.1853,         7.1058,         7.019,         7.0002, 6.9472,         6.8591,         6.8388,         6.8345,         6.8183))


INITS
list(h1=0.1,h2=0.1,h3=0.1,a1=2,a2=2,a3=2,
lambda=1,alpha=0.1,beta=0.1,
gamma=100,r=0.1,A=c(0.1,0.1),B=c(0.1,0.1),C=c(0.1,0.1,0.1))