This will allow you to set up your own maximum likelihood problems for models which are not included in the program already. See, also, topic Optimization' for details on how to handle the optimization procedure. The last expression is the one being minimized, so it does not have a name.
Any expression can use the name of any previous expression, as many times as desired.
If the function you are minimizing is NOT a sum of terms, just specify it as usual. If you forget to set the sample, you will still get the right answer. But, it will take longer, because you will be minimizing N times the function. Minimizing a sum of terms is identical to the preceding except that your FCN expression will involve one or more variables, and you will not reset the sample. There are no residuals.