I've just added a LogNormal.Estimate function for exactly that (maximum likelihood) that will be included in the next release.
In the meantime, simply take the natural logarithm of each sample and then compute mean (-> mu) and standard deviation (-> sigma) of these resulting samples.
In the meantime, simply take the natural logarithm of each sample and then compute mean (-> mu) and standard deviation (-> sigma) of these resulting samples.