just be careful don't end up yelling again :-)
If you really think you are right, I don't think it is necessary to apologize. Some apologies are like tearing up a healing wound. It is better not to say anything, just show your respect in public and hopefully this will pass. If your boss is a person likes to hold grudge, then she will hold it either you apologize or not. But of cause it depends on your scenario and situation.