Weibull parameter estimates
parmhat = distfun_wblfit( data )
a matrix of doubles, the data, data>=0
a 1-by-2 matrix of doubles, the parameters of the Weibull distribution
Estimates the parameters of the Weibull distribution with maximum likelihood method. The parameters are chosen so that they minimize the negative log-likelihood function.
The implementation first estimates the parameters by the method of moments. This first estimate is then used a the starting guess for the optimization algorithm.