TODO

• Allow for n_epochs=0 in SimDP.run() so initial grid can be had

• Specify n_next_epochs in SimDP.run() to split sim into segments

• Return successive cell density grids to Python after each sim segment

• Mod test py to generate a set of successive grids

• Mod test nb to generate a set of successive grid images

• Generate an animation from such a set of images

• Test periodic topology again

• Implement distinct x/y/z topologies

• Implement fixed value bcs on each boundary (done for 2d)

• Implement fixed flux bcs on each boundary (done for 2d)
• Complete bcs for 1d

• Revise test scripts following API changes

• Develop DP scaling-validation tests