Dustin Hoffman and Susan George play an American mathematician and his English wife in Straw Dogs (1971), a thriller directed by Sam Peckinpah. In this movie there is quite a lot of madness (rampant violence) but no math to speak of, other than the main character is supposed to be a mathematician. He is timid at first, and people think he will be a push-over. Maybe the author's idea was that everybody would be surprised when this seemingly timid, unimpressive character is the one surviving man after rescuing, and avenging his wife from the thugs who attacked them.