I am trying to build a deck that will be a rectangle but with semi-circle ends resulting in kind of an oval. How do I frame and floor the semi-circlular parts of the deck? I have attached a very simple drawing of the general shape. Thanks

I once built one that was round on one end.I ran all the joist to the longest point then I put a nail in the two out side joist at the shortest points.then I used a 16 foot piece of strapping and flexed it from the short points out to the longest.marking each joist.the I check the angle of each mark and set my saw to each angle and cut them.then used plywood (a few layers ) as my outside rim.now your if your circler ends are tighter than mine was you may need something more plyable than stapping and you may need more layers of thinner plywood.there is also a plywood called wacky wood it's a very,very flexable quarter inch plywood.