Re: weibull distribution
- To: mathgroup at smc.vnet.net
- Subject: [mg31387] Re: [mg31375] weibull distribution
- From: BobHanlon at aol.com
- Date: Wed, 31 Oct 2001 19:59:07 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
In a message dated 2001/10/31 3:46:48 AM, chandrika at ittc.ukans.edu writes:
>I am trying to fit data to weibul distribution. Is there a way to do
>using mathematica?
>
Needs["Statistics`ContinuousDistributions`"];
data = RandomArray[WeibullDistribution[5., 5.], 100];
logPDF[x_] := Evaluate[PowerExpand[Log[PDF[WeibullDistribution[a, b], x]]]];
logProd = Plus @@ (logPDF[#]& /@ data);
eqnMLE = ((D[logProd, #] == 0)& /@ {a, b});
soln = FindRoot[eqnMLE, {a, 1.}, {b, Mean[data]}]
{a -> 4.99725689108074,
b -> 5.033979933866775}
Bob Hanlon
Chantilly, VA USA