Re: [R] Estimating parameters of 2 phase Coxian using optim

2007-03-08 Thread Gad Abraham
Laura Hill wrote: > > > On 7/3/07 00:15, "Gad Abraham" <[EMAIL PROTECTED]> wrote: > >> Andy Fugard wrote: >>> Hi There, >>> >>> Perhaps the problem is the line >>> >>> loglik<-log(p %*% expm(Q * y(i)) %*% q) >>> >>> You mention that y is a vector but here you're treating it as a >>> fun

Re: [R] Estimating parameters of 2 phase Coxian using optim

2007-03-08 Thread Laura Hill
On 7/3/07 00:15, "Gad Abraham" <[EMAIL PROTECTED]> wrote: > Andy Fugard wrote: >> Hi There, >> >> Perhaps the problem is the line >> >> loglik<-log(p %*% expm(Q * y(i)) %*% q) >> >> You mention that y is a vector but here you're treating it as a >> function. Maybe try >> >>

Re: [R] Estimating parameters of 2 phase Coxian using optim

2007-03-06 Thread Gad Abraham
Andy Fugard wrote: > Hi There, > > Perhaps the problem is the line > > loglik<-log(p %*% expm(Q * y(i)) %*% q) > > You mention that y is a vector but here you're treating it as a > function. Maybe try > > loglik<-log(p %*% expm(Q * y[i]) %*% q) > > ? > > Don't have a clue

Re: [R] Estimating parameters of 2 phase Coxian using optim

2007-03-06 Thread Andy Fugard
Hi There, Perhaps the problem is the line loglik<-log(p %*% expm(Q * y(i)) %*% q) You mention that y is a vector but here you're treating it as a function. Maybe try loglik<-log(p %*% expm(Q * y[i]) %*% q) ? Don't have a clue about the correctness of the contents of cox2.

[R] Estimating parameters of 2 phase Coxian using optim

2007-03-06 Thread Laura Hill
Hi, My name is Laura. I'm a PhD student at Queen's University Belfast and have just started learning R. I was wondering if somebody could help me to see where I am going wrong in my code for estimating the parameters [mu1, mu2, lambda1] of a 2-phase Coxian Distribution. cox2.lik<-function(theta,

[R] Estimating parameters of 2 phase Coxian using optim

2007-03-06 Thread Laura Hill
Hi, My name is Laura. I'm a PhD student at Queen's University Belfast and have just started learning R. I was wondering if somebody could help me to see where I am going wrong in my code for estimating the parameters [mu1, mu2, lambda1] of a 2-phase Coxian Distribution. cox2.lik<-function(theta