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Show HN: A basketball hoop to maximize shots that go in [video]

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Re: Show HN: A basketball hoop to maximize shots that go in [video]

#41

Post by mywittyname »

milesvp wrote: post #21
mNovak wrote: post #13

Does it bug anyone else not to have the analytic solution?

Fun story. I was in college taking differential equations. And I was faithfully attempting to apply what I'd learned in class, and having a somewhat hard time at it (this was before I realized how useful matlab was). When I was doing some research on the side, and I learned that the vast majority of differential equations are unsolvable, you can only approximate an answer. After that, I was thouroughly annoyed at was…

This should be solvable without differential equations, since it is basically a parabolic antenna with an off-axis feed.

Re: Show HN: A basketball hoop to maximize shots that go in [video]

#42

Post by gnulinux »

nabla9 wrote: post #10

"Who is Monte Carlo?" Monte Carlo is for Europe what Las Vegas is for the US. The first name that comes to mind when you think gambling. Monte Carlo method is repeated random sampling to obtain numerical results. Monte Carlo algorithms are heuristic algorithms that solve problems with random process that can give wrong answers. Las Vegas algorithms are algorithms that solve problems with randomness but get always cor…

Another way to put this is:

Monte Carlo Algorithm: Always fast, probably correct.

Las Vegas Algorithm: Probably fast, always correct.

Atlantic City Algorithm: Probably fast, probably correct.

Re: Show HN: A basketball hoop to maximize shots that go in [video]

#43

Post by dwightgunning »

milesvp wrote: post #21
mNovak wrote: post #13

Does it bug anyone else not to have the analytic solution?

Fun story. I was in college taking differential equations. And I was faithfully attempting to apply what I'd learned in class, and having a somewhat hard time at it (this was before I realized how useful matlab was). When I was doing some research on the side, and I learned that the vast majority of differential equations are unsolvable, you can only approximate an answer. After that, I was thouroughly annoyed at was…

Thanks for a great anecdote. While I feel I'm pretty good at recognising that "done is better than perfect", I'm not as good at realising when "near enough is good enough". For some reason approximations usually don't sit well with me... something I can work on for sure.

Re: Show HN: A basketball hoop to maximize shots that go in [video]

#44

Post by dang »

numuliank wrote: post #11

Nope, expected something interesting, but this is based on a boring brute-force simulation. He did hint at using a parabolic shape, like in satellite dishes. Why not use some actual calculus and differential equations to figure out the optimal parabolic-like shape here?

It's great that you know more, but can you share what you know without putting others or their work down? Doing the latter really poisons the well here.

A much better pattern than "Nope, expected something interesting" is to first affirm something that the author got right or did well, and then build on that with suggestions for refinement, further development, learning. There's plenty of opportunity to show how much you know that way, plus you won't also come across as an internet jerk.

Keep in mind that project creators and authors are often reading these threads, and one nasty comment makes more of an impression than the rest of a thread put together. A single bee sting is more memorable than a field of butterflies. It's too bad that it doesn't work the other way around, but the pattern is super clear. Even the thread the other day with the C Committee guys, which was one of the best technical threads HN has ever hosted, made this impression on them: "Wow, I had no idea people were so mad about locales" (not a direct quote). I hadn't noticed, and when I found the comments they didn't even seem that mad.

Re: Show HN: A basketball hoop to maximize shots that go in [video]

#46

Post by mywittyname »

Misdicorl wrote: post #38
soheil wrote: post #32

Is this not something that just an optics equation in Physics would give you? Specially if not taking the radius of the ball into effect.

Depends on the importance of a couple effects that light is immune to (at least for an optics equation) 1) gravity post impact with backboard 2) impact angle for a given (start, backboard) tuple depend on velocity and launch angle for a basketball, but are always the same for light. Also the impact angle for the basketball and light are very different

I think it's safe to ignore both of these factors at this scale. 1) The effects of gravity is bounded and negligible on the surface of the Earth. 2) (I suspect) the wideness of the launch angle and hoop size are probably directly proportional, so you could shape the back board based on a direct impact to get a point to center the hoop on. The hoop can only get so big and still be considered reasonable.

Re: Show HN: A basketball hoop to maximize shots that go in [video]

#47

Post by mrspeaker »

soheil wrote: post #32

Is this not something that just an optics equation in Physics would give you? Specially if not taking the radius of the ball into effect.

I think you gotta take the radius of the ball into account - that's the only bit he messed up on. (And if we can just have any-old assumptions, then it seems like the optimal solution is to make the entire backboard a hoop!)

Re: Show HN: A basketball hoop to maximize shots that go in [video]

#48

Post by Animats »

The first 10 seconds pretty much covers the subject.

It's not the hoop, it's the shape of the backboard, which is a reflector formed to focus the ball on the target.

Now, the really cool thing would to build a flat backboard with controlled bounce properties. Interesting 3D printing problem. That would look like an ordinary backboard but still focus bounces.

Re: Show HN: A basketball hoop to maximize shots that go in [video]

#49

Post by jansan »

Animats wrote: post #48

The first 10 seconds pretty much covers the subject. It's not the hoop, it's the shape of the backboard, which is a reflector formed to focus the ball on the target. Now, the really cool thing would to build a flat backboard with controlled bounce properties. Interesting 3D printing problem. That would look like an ordinary backboard but still focus bounces.

Another idea would be a hoop controlled by servos that always moves the hoop where the ball is going.

Re: Show HN: A basketball hoop to maximize shots that go in [video]

#50

Post by carlob »

hencq wrote: post #37
soheil wrote: post #32

Is this not something that just an optics equation in Physics would give you? Specially if not taking the radius of the ball into effect.

Maybe, but as he explains a normal parabola (like a satellite dish) wouldn't work, since the shots themselves are arced because of pesky gravity. I thought using a Monte Carlo analysis and finding a fixed point was actually a very clever way to solve it.

Yeah but the acceleration from gravity is constant so maybe there is just a (possibly non linear) change of coordinates that can be applied to the regular paraboloid.

Also a paraboloid would work only for rays that are parallel to one another.

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