Collapsing a and b variables to linkID

[rickdonnelly]

I cannot tell that the variables a and b are used for anything in this package. It makes sense to carry them along so that data problems can be easily traced in the original network databases, but otherwise they appear superfluous. Can we please replace a and b with a single linkID field? Seems like it'd be trivial to concatenate a and b for platforms that still use them (e.g., Emme, Cube), and would require no translation for those that already use IDs (e.g., TransCAD, MATSim).

[dkyleward]

Where do you see a and b? You're right that I've never used them.

[rickdonnelly]

If you look at the data schema in R/data.R you will see them listed there. Since the functions seem to ignore all extraneous link data I assumed that those variables listed are used in one or more functions. So, maybe the focus should be on revisiting the list of variables in that file rather than assuming that they're all keywords expected by one or more functions.

[gregmacfarlane]

The original dataset we used to build the package came from Cube. I agree that we can concatenate and move forward with a single linkid.

[dkyleward]

@rickdonnelly it will be easier for me if you just add me as a collaborator to the repo. That way I don't have to fork for each change.