Re: Please help me.....
- To: mathgroup at smc.vnet.net
- Subject: [mg91098] Re: Please help me.....
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Wed, 6 Aug 2008 05:04:47 -0400 (EDT)
- References: <g791ih$9n3$1@smc.vnet.net>
Hi, n = 69; x2 = {5, 6, 5.5, 5, 8.4, 4.5, 4, 6, 7, 6, 7, 8, 5.4, 5, 4, 3.5, 4.5, 6.5, 5, 3.5, 5.7, 5.8, 5, 4.8, 4.5, 5.8, 3.2, 6, 4, 6, 7, 6.5, 10.7, 7, 4.7, 7, 8.3, 10, 6.5, 4.9, 3.4, 9, 6, 3.1, 5, 4.8, 4, 6, 6, 5.6, 4.2, 4.3, 4.5, 8.4, 8.6, 5.8, 6.8, 4.8, 3.4, 8, 8, 8.3, 8, 4.5, 6, 4.5, 7, 7, 8}; BurrDistribution[x2_, c_, k_] := (c*k)*(x2^(c - 1)/(1 + x2^c)^(k + 1)) pdf = BurrDistribution[x2, c, k] logl = Plus @@ Log[pdf]; maxlogl = NMinimize[{-logl, c > 0 && k > 0}, {c, k}] mle = maxlogl[[2]] ?? Regards Jens Dewi Anggraini wrote: > Hi all > > I'm an international studentat RMIT University Melbourne. Currently, I'm > doing my master degree in Statistics and Operations Research. This > following 6 months will be my last semester to finish my master degree. > Therefore, I have been doing minor thesis about "estimating unknown > parameter of Burr distribution" by using Mathematica. > > I was wondering if this forum could assist me to detect where I got wrong > with my program since it works for Burr distribution in some data but not > with my data. Additionally, this program (I attached my program along with > my data) also works for non-normal distribution, such as Gamma and Weibull > since my data are non-normally distributed and they are closely to gamma > and weibull distribution. > > The data are treatment time of cervical cancer patients in a hospital. > Frequently, they come to the hospital in the late satge of cancer, thus > the minimum time for the treatment is 2 days and the maximum treatment on > the data is 21 days. > > The following is my program to run MLE of Burr distribution. However, > it comes up with "comment" results in finding the coefficient of unknown > parameters when I run it. > > > n = 69; > x2 = {5, 6, 5.5, 5, 8.4, 4.5, 4, 6, 7, 6, 7, 8, 5.4, 5, 4, 3.5, 4.5, > 6.5, 5, 3.5, 5.7, 5.8, 5, 4.8, 4.5, 5.8, 3.2, 6, 4, 6, 7, > 6.5, > 10.7, 7, 4.7, 7, 8.3, 10, 6.5, 4.9, 3.4, 9, 6, 3.1, 5, 4.8, 4, > 6, > 6, 5.6, 4.2, 4.3, 4.5, 8.4, 8.6, 5.8, 6.8, 4.8, 3.4, 8, 8, > 8.3, 8, > 4.5, 6, 4.5, 7, 7, 8}; > BurrDistribution[x2_, c_, > k_] := (c*k)*(x2^(c - 1)/(1 + x2^c)^(k + 1)) > pdf = BurrDistribution[x2, c, k] > logl = Plus @@ Log[pdf] > maxlogl = FindMinimum[-logl, {c, 1}, {k, 2}] > mle = maxlogl[[2]] > > > > Please assist me in finding the problem I face now. This is very important > for my thesis. > > I look forward for any comments and advices, thank you. > > Regards, > Dewi