Nice guy. Good lecturer. His lectures are inspirational and organized. I skipped most of the lectures though.

Midterm2 and Final were hard but he curved the whole class. If you study hard and got relatively good grade during the quarter, he wont be too harsh

Casteels is the only professor I haven't liked. He would mark me down for correct answers in a form not of his preference. I even verified with other professors. Easy material, though. He would shut me down when asking questions not related to the homework or exams, but out of genuine interest in the subject. Everyone else seems to like him, though

Really enjoyed his 108A class. The lectures are well organized and his notes were clear. The midterms were pretty easy and he gave extra credits for the final. Always available during his office hours and even gave extra office hours right before the exams. Great Professor! Definitely will take his class again

Karel is a super nice guy. Lectures are understandable and test are fair, but hw can be graded harshly. Would recommend taking for any math class at UCSB.

Professor Casteels is organized, clear and easy on the eye. However, I dont know whether hes just busy with other things in his life that whenever I try to talk to him, I couldnt tell hes being shy, offended, or straight up doesnt care....(it could be my fault). Trying to talk to him is sure a frustration, but beside that all good.