Re: [R] invalid function value in 'nlm' optimizer

2015-04-29 Thread Duncan Murdoch
On 29/04/2015 9:49 AM, Hanze Zhang wrote: How should I do? The issue happened on log likelihood function? I imagine it's the log(x[delta==1]) term that is turning the result into a vector. Duncan Murdoch On Tue, Apr 28, 2015 at 11:06 PM, William Dunlap > wrote:

Re: [R] invalid function value in 'nlm' optimizer

2015-04-29 Thread Hanze Zhang
How should I do? The issue happened on log likelihood function? On Tue, Apr 28, 2015 at 11:06 PM, William Dunlap wrote: > Your function ln() does not return a scalar. >> ln(theta=c(1,2)) >[1] 48.5342640972 48.5342640972 48.5342640972 48.5342640972 48. > 5342640972 > > > Bill Dunlap > TIB

Re: [R] invalid function value in 'nlm' optimizer

2015-04-28 Thread William Dunlap
Your function ln() does not return a scalar. > ln(theta=c(1,2)) [1] 48.5342640972 48.5342640972 48.5342640972 48.5342640972 48.5342640972 Bill Dunlap TIBCO Software wdunlap tibco.com On Tue, Apr 28, 2015 at 6:40 PM, Hanze Zhang wrote: > I still cannot solve the problem: 'invalid functio

Re: [R] invalid function value in 'nlm' optimizer

2015-04-28 Thread Hanze Zhang
I still cannot solve the problem: 'invalid function value in 'nlm' optimizer' I want to get the MLE for theta[1] and theta[2], my code is below: x <- c(2,5,3,7,3,2,4) delta <- c(1, 0, 1, 1, 1, 0, 1) # -log likelihood #alpha<-theta[1] #lamda<-theta[2] ln<-function(theta,x1,x2 ) { -sum(del

Re: [R] invalid function value in 'nlm' optimizer

2015-04-28 Thread Duncan Murdoch
On 28/04/2015 2:43 AM, Hanze Zhang wrote: > Hi, R users, > > > I am using nlm function to get the MLE of parameter alpha and lambda from a > parametric survival model (Weibull distribution). However, this message > always came out: ' invalid function value in 'nlm' optimizer'. Could anyone > hel

Re: [R] invalid function value in 'nlm' optimizer

2015-04-28 Thread Bert Gunter
Why are you doing this instead of using the survival package? Bert On Tuesday, April 28, 2015, Hanze Zhang wrote: > Hi, R users, > > > I am using nlm function to get the MLE of parameter alpha and lambda from a > parametric survival model (Weibull distribution). However, this message > always

[R] invalid function value in 'nlm' optimizer

2015-04-27 Thread Hanze Zhang
Hi, R users, I am using nlm function to get the MLE of parameter alpha and lambda from a parametric survival model (Weibull distribution). However, this message always came out: ' invalid function value in 'nlm' optimizer'. Could anyone help me? Code is project<-read.table(file="C://data.txt",