[R] maximum likelihood estimate

[suhaila at mel.fs.utm.my]

Hi!
Recently I try to find the method  maximum
likelihood for gamma,weibull,Pearson type III,Kappa Distribution,
mixed exponential distribution, skew distribution.
I have tried function ms() for gamma two parameters and weibull two
parameters.It works but not for Pearson type III. I have problem to find
the likelihood function for mixed exponential distribution and kappa
distribution.
So can anyone tell me the programming for those functions?
especially in finding their maximum likelihood,because I have trouble to
write down the likelihood function for mixed exponential distribution and
the other two.If possible ,how to get the hessian matrix?
Currently I am using SPlus 6.2.

Thanks.
suhaila