Displaying 2 results from an estimated 2 matches for "pisotive".
2009 Dec 06
5
optim with constraints
...he method of meximum likelihood
to fit a Weibull distribution to my survival data. I use "optim" as
follows:
optim(c(1, 0.25),weibull.like,mydata=mydata,method="L-BFGS-B",hessian
= TRUE)
My question is: how do I setup the constraints so that the two
parametrs of Weibull to be pisotive? Or should I use other function
like"nlm"?
Many thanks! Any comments are greatly appreciated!
Steven
2009 Dec 06
2
MLE in R
...the method of meximum likelihood to fit a Weibull distribution to my survival data. I use "optim" as follows:
optim(c(1.14,0.25),weibull.like,mydata=mydata,method="L-BFGS-B",hessian = TRUE)
My question is: how do I setup the constraints that the two parametrs of Weibull to be pisotive?
Many thanks! Any comments are greatly appreciated!
Steven
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