In The Sun Also Rises, how does the setting complement the novel?

Well, Hemingway was actually watching the bullfights in spain when he decided that that would make an interesting basis for a novel, so in a way the setting was the springboard which originated the novel. Also, setting the story around a bullfight allows him to compare the characters to bulls and steers as a way of exploring their femininity/masculinity and their attitudes.

I hope this helps. I'm not a professor or anything, I'm just a student writing an essay on a book by a masochist that I hate. But a quick google search should probably verify the above information - as well as the internet verifies anything... as well as give you some ideas regarding the bull/steer/character comparisons.