Are you kidding, of course I have smashed my racquet on the gorund when I'm angry.
To control my anger, which I am actually doing alot better with, I ALLWAYS think to the positive side.
1) If my opponent says the ball was out but I know it was in, I simply hit the ball to the same place only slightly inside of where it was before. Because most likely that is their bad side (if you are positive its in) and are trying to get away with it.
2) If I lost a set, I think about all of my opponents mistakes and play off of them.
3) If in general I really don't like my opponent and am angry I have to play them, I hit them with the ball. Of course you make it at their feet/ankles, so its a less obvious hit.
4) Just try and stay calm in general. Thats allways the best :-)
Hope I helped in some odd way, of course whoever you are playing is not going to be happy with my advice, but o-well.