Duffing Spring Simulation about sympy

[moorepants]

This looks nice. My suggestion is that we add the example in the documentation. We can use numpy, scipy, and matplotlib in the docs. If we create an explanatory page about actuators in the prose documentation, then you can place it there. Whether you put it "tutorials", "how-to guides", or "explanations" depends on how you present the material. I don't really understand the difference in the three, but maybe you can make a judgement. Eventually we need to move all of the prose documentation in the physics.vector and physics.mechanics sections into one of these top level sections, so you can be the first to establish where these things go. I'm guessing this is a little long of an example to belong in the docstring. @tjstienstra thoughts?

[tjstienstra]

This is indeed a really nice example, where you show that we can reproduce the results with a simulation. I agree that it would be best not to put it in the docstring, but in another location. Previously, I would have put examples in physics/mechanics/examples, but I think that "tutorials" is probably the place we should start moving our examples to.

[eh111eh]

Thanks for the feedback! How about creating two directories: sympy.doc.src.tutorials.mechanics to add the Duffing spring simulation and move other examples for physics.mechanics, and sympy.doc.src.tutorials.vector to move examples for physics.vector?

[moorepants]

In the tutorials directory: https://github.com/sympy/sympy/tree/master/doc/src/tutorials we should probably follow the directory structure of the sympy subpackages. For example there is a sympy/vector and sympy/physics/vector, so for long term organization, we should have docs/src/tutorials/physics/mechanics (I see that we didn't follow this with biomechanics but we can correct that, especially since sympy 1.13 is not yet released.

[moorepants]

If you go about moving any examples from the old location, then you will need to set up link redirects. We have a sphinx plugin that reasonably automates that.