I started a PhD in US wanted to study machine learning. Instead of that I cleaned experimental data (coming from human-related experiments), without any algorithmic endeavur or learning anything new. The choice of lab was pure, since they are supposed to use machine learning but not explicitly study it, but I chose it because of personal reasons (they would allow me to visit my family in my country more often). I regret it, since I see now that they do not use machine learning at all. I told my professor, after a year, that I want to stop at masters and he got angry. He agreed but I get the feeling he will not allow me to do any kind of research on the masters, and he'll probably make my life hell. I want to apply for a new PhD but since I have not done substantial research for the past year, I don't think I have good chances of getting accepted in a better PhD program. How should I handle this case with my professor? Can he not allow me to even take a masters? of course asking for a recommendation letter is out of question..