[REVIEW]Feature adding fractional differencing computation

[yidong72]

This is to address this issue by adding fractional differencing computation. It is not finished yet but the main computation functions are implemented with the unittests. It can start the review process. I am going to add computation node and python notebooks in the next commit.

[yidong72]

The new notebook is added. It is ready to review.

[avolkov1]

A few minor remarks. I'm still running the notebook. Looks good though.

[yidong72]

All the review points are addressed

[avolkov1]

Everything looks good to me. My only suggestion would be to unpack the tuple at the end of the notebook explicitly. Like this:

(lineplot,) = task_graph.run(
    outputs=outlist,
    replace=replace_spec)

# display plot in jupyter
lineplot

Instead of

o_gpu = task_graph.run(
            outputs=outlist,
            replace=replace_spec)
o_gpu[0]

It wasn't clear to me at first that o_gpu contained the figure plot that was being displayed even though it was discussed in the preceding cells of the notebook.

That would be the only change I would suggest. If you want to make this change let me know, otherwise I'll merge this.

[yidong72]

I did the changes in the notebook. Ready to get it merged.