linmod<-function(prior,X,y,unknown=TRUE)
{Xt<-t(X)
 Cd<-Xt%*%X
 Xty<-Xt%*%y
 b0<-prior$b
 betahat<-solve(Cd,Xty)
 n<-length(y)
 C0<-solve(prior$V/prior$v)
 C1<-C0+Cd
 b1<-solve(C1,(C0%*%b0+Cd%*%betahat))
 res<-y-X%*%betahat
 Sd<-sum(res^2)
 if (unknown)
    {d1<-prior$d+n
     R<-t(b0)%*%C0%*%b0 + t(betahat)%*%Cd%*%betahat - t(b1)%*%C1%*%b1
     nvd<-Sd+R
     v1<-(prior$d*prior$v + nvd)/d1
     v1<-v1[1,1]
     }
 else
    {v1<-prior$v
     d1<-0
     }
 V1<-v1*solve(C1)
 result<-list(d=d1,v=v1,b=b1,V=V1)
 result
 }