Added ProMPs and Kinematics functionalities

[souljaboy764]

Implemented Probabilistic Movement Primitives, specifically the conditioning aspect along with a general kinematics base class to perform forward and inverse kinematics. This needs to be extended for specific robots, providing the corresponding forward model. The code is adapted from https://github.com/sebasutp/promp

TODO:

• Add examples for using the ProMPs and conditioning
• Implement the EM-based learning for ProMPs as in https://github.com/sebasutp/promp

[souljaboy764]

Need to test a bit more before this can be merged

[souljaboy764]

Tested the ProMP and Kinematics codes and they are working now.
Need to add examples to show how to use them.

[joe-campbell]

Sorry for the late followup, somehow I missed when this was opened.

From your last comment, if you could add examples for how to use this so I could better understand the changes then that would be great! Something like a minimal tutorial script or such.

[souljaboy764]

I have added an example file at examples/promp_example.py and have also added a notebook about it as well.

[souljaboy764]

I was having issues when importing the package in python3 due to the relative imports. I have changed the imports in the files to support python3 style syntax. I am now able to run the basic examples on python3.

[hbaradius]

We should add souljaboy to the list of contributers to the IntPrim library. Very cool stuff!

[joe-campbell]

Thanks for the latest push! Apologies for the lack of activity on my end, I was caught up in some other work. I will look at this in some detail over the weekend try to merge it. By the way, I noticed there are some hard coded paths in this latest commit, e.g.,

with open('/home/corobi/playground/intprim_test/strike_mov.npz','rb') as f:

Can this be changed such that any path is able to be set as a parameter? Otherwise other people won't be able to run these tests without modifying the source code first.

[souljaboy764]

Oh, I must have overlooked this.
I'll add the path to be given as a command line argument and add a comment on the usage.

[souljaboy764]

@joe-campbell Any suggestions on how to do that for the python notebook version of the example? Or should I just include the strike_mov.npz file from https://github.com/sebasutp/promp which I've used for the examples?

[joe-campbell]

Hmm, there's no license given in that other library so I would prefer not to include any other data files directly. How about if we just provide an instruction in the notebook to download it and unzip it to a relative path location that the notebook looks for?

The notebook won't run without that, but I think it's ok. And the locally compiled version which is pushed up to github will still show what it looks like when that file is present.

[souljaboy764]

I updated the examples and the notebook as well. I had also changed some of the code to be python3 compatible in one of the previous commits. It works on my system but would need to be tested further before claiming it to be properly python3 compatible.