Actually pretty chill and kind. As has been said he provides some good notes. He's flexible with students. I don't understand why there's so many bad reviews. Complaints about his "loudness" or otherwise are just because of his accent. Ye is one of the few prof in the dept to be highly accomplished, but yet not be overly demanding with his students

The syllabus was just homework midterm final, no course description, no professor email, nothing. Lectures are arguably worse than reading the book on your own. Ye goes incredibly slow through class and doesn't explain any ideas or do any examples. Personally, I just take notes from the textbook instead. Avoid taking his class if you can.

Course material is straight forward. Always presents example proofs and often shows different ones than from the textbook to let you see the multiple ways to approach things. Lecture is sometimes silly when he spends the whole time on one big proof but typically the concept demonstrated is essential. Tests on the basics, nothing tricky.

He's a terrible professor He has office hour but seldom there at office. The tests are out of wall. He cancelled our weekly homework because there is no grader. Then he adds the percentage of homework to the final. He sometimes speaks Chinese in class. He always skip the questions that asked in class even makes me think he doesn't know the answer.

The worst teacher I have ever had! AVOID AT ALL COSTS! He has made it clear he prioritizes his research and grad work over our course. Spends as little time on our class as possible. We were unable to get a grader for our homework and he refuses to provide solutions. No way of knowing where you stand in the class. TERRIBLE PROFESSOR!!

I can't not even explain how bad this teacher is. I can't understand him, he writes like a 2nd grader, he won't tell us how many/when our midterms are. There are no practice test. He puts in no effort to help you do well or learn. I actually like math but I have never dreaded a class more.