Re: [R] fitting lognormal censored data

2012-09-03 Thread Salma Wafi
Dear Berend Thanks for your response. I will write my code and estimate the parameters using functions optim() or nlminb(). For the code that I am trying to build for estimation the parameters using mle via EM ahgorithm, I will rewrite it and reformulated my question about, but before that I nee

Re: [R] fitting lognormal censored data

2012-09-03 Thread Berend Hasselman
You should keep your replies on the R-help list by always cc-ing to that list. As you were asked to do in a previous thread you started. As I demonstrated in a previous reply, the R function optim() is perfectly capable of minimizing or maximizing your likelihood function. Your attempts at using

Re: [R] fitting lognormal censored data

2012-08-31 Thread Rich Shepard
On Thu, 30 Aug 2012, Salma Wafi wrote: I am trying to get some estimator based on lognormal distribution when we have left,interval, and right censored data. Take a look at the NADA package. For left-censored data you can use cenmle with dist = 'lognormal'. Survival analyses work well for ri

Re: [R] fitting lognormal censored data

2012-08-31 Thread Berend Hasselman
On 31-08-2012, at 03:54, Salma Wafi wrote: > Hi , > I am trying to get some estimator based on lognormal distribution when we > have left,interval, and right censored data. Since, there is now avalible > pakage in R can help me in this, I had to write my own code using Newton > Raphson method

[R] fitting lognormal censored data

2012-08-30 Thread Salma Wafi
Hi , I am trying to get some estimator based on lognormal distribution when we have left,interval, and right censored data. Since, there is now avalible pakage in R can help me in this, I had to write my own code using Newton Raphson method which requires first and second derivative of log likel