Vector cells

[mehulrastogi]

This branch addresses the issue discussed in #71 .

This has the following changes:-

• Introducing a new class called Vector Class. OVCs/BVCs will be child classes of this class.
  • Using this class the user can now have any custom manifold if they so choose (in a specific API)
  • extends the display manifolds functionality of FoV to all types of Vector Cells (allocentric and egocentric)
  • Solved some bugs related to display_manifolds
  • Now the default manifold maps are a part of the utils. Also have the 'hartley'/'uniform'/'random' manifolds

A small caveat for the OVCs. Now instead of being randomly assigned to objects. Now one can passed a preferred object type

[mehulrastogi]

@TomGeorge1234 you were right calculating the relative positions of the cells in the display_manifold function does not cause major speed problems. Adopted that now.

So essentially one would be able to change the tuning_distance just by changing this object variable

[TomGeorge1234]

I like it. More convinced now that this is the most sensible way to do things. Some proposed changes (mostly linguistic):

• Instead of "manifold_function" lets call this parameter "cell_arrangement" which can be (for now) if ["random" ,"uniform_manifold","diverging_manifold"]. This allows us to distance ourselves from the terms manifold and hartley which are a bit specific/loaded (we can use them in the comments to clarify).
  • The method _create_manifold() should be renamed set_vector_cell_parameters
  • The utils functions get_uniform_manifold() and get_hartley_manifold() could go to create_uniform_radial_assembly() and create_diverging_radial_assembly()
  • display_manifold() --> display_vector_cells() but here we should have an alias function dispaly_manifold() which links to the new names and throws a deprecation warning.
• VectorCells doesn't need a "name" parameters
• For plotting might look into vectorising with matplotlib.collections.EllipseCollection(widths, heights, angles, *, units='points', **kwargs) as opposed to looping over the cells in a for-loop. Tbh I don't know if ellipse collections actually just does a loop in which case it may not be worth the effort. I also could figure out how to set the position of each ellipse, only the angles and sizes.
• Deprecation warnings on the old contribs FoVCells to send people to the new flashy fov vector cells in Neurons.py

Optional but not essential

• get_hartley_manifold() has a fixed parameter inside it called beta. This determines the rate of perspective increase and I found that 5 is a nice amount so hard set it at that. We might make this a parameter of the function. Importantly it is the same beta as that which defaults to 12 in VectorCells line 1100 so maybe theres a saving we could use here.

I'll think of more and we can chat tomorrow. Getting there and thanks again for the work!

[mehulrastogi]

Seems like the checks are running now :)