Dear Statalisters,

I have seen commands in -ml- that use as an option -gtol()-. For example, in this past post: https://www.stata.com/statalist/arch.../msg01091.html the following command is used:
ml maximize, tech(nr bhhh dfp bfgs) tol(1e-12) gtol(1e-12) force Another example is here: https://www.statalist.org/forums/for...ction-frontier which uses:

ml max, difficult gtol(1e-5) nrtol(1e-5)

There are many other examples.

But searching the stata manual, https://www.stata.com/manuals13/rml.pdf I don't find any explanation about gtol. I also didn't find gtol anywhere mentioned in the full (2,997 page) stata manual. Please let me know why this may be, and where I can learn more about what this ml option does.

Thanks,
Hewan