I am researching a software reliability model that has many parameters that need to be estimated. I want to use a maximum likelihood estimator (MLE) to estimate those parameters, but my model is too complicated to derive the log-likelihood function (namely LL in the following picture) from the likelihood function (namely L in the following picture).

When I try to execute Log[L] in Mathematica, I don't get the expected answer (LL). So my question is, how can I get expected answer after taking the log of the equation? Or can Mathematica not do this operation?

Link of code:https://www.dropbox.com/s/e81ndt3kgdq5dsw/GO_model.nb

enter image description here

  • 3
    $\begingroup$ Please look up Simplify, FullSimplify and ComplexityFunction. Also search this site for useful posts on those. $\endgroup$ – rm -rf Sep 16 '13 at 16:37
  • 2
    $\begingroup$ Can you add the exact code instead the pictures of it ? $\endgroup$ – Sektor Sep 16 '13 at 16:59
  • $\begingroup$ Sorry, I am rookie in here, so I directly post the link for code in the picture. $\endgroup$ – Steven Chen Sep 16 '13 at 17:16
  • $\begingroup$ I try to input SuperLog[On],but I just get output SuperLog[On]. $\endgroup$ – Steven Chen Sep 16 '13 at 17:34
  • $\begingroup$ @user2336074 Unfortunately the SuperLog thing referenced in the top answer is only available by purchasing the add-on package mathStatica. $\endgroup$ – Mr.Wizard Sep 16 '13 at 17:41