[wpiunits] Add Feedforward unit types

[narmstro2020]

I'm the kind of person who will use the Units class for these constants and I wanted to test the waters.

Hence why this is a draft. Also not 100% sure how the pregen will go.

Also I've only added one for kV for linear velocity.

Feedback (Haha get it) is always appreciated.

[narmstro2020]

/pregen

[narmstro2020]

/pregen

[narmstro2020]

So what's causing the pregen to fail?

[Gold856]

The pregen command wasn't updated to regenerate wpiunits. I'll work on fixing this, but in the meantime, if you can install Python and Jinja (pip install Jinja2), I recommend you do so and just run python wpiunits/generate_units.py and commit the changes.

[narmstro2020]

The pregen command wasn't updated to regenerate wpiunits. I'll work on fixing this, but in the meantime, if you can install Python and Jinja (pip install Jinja2), I recommend you do so and just run python wpiunits/generate_units.py and commit the changes.

Thank you. Am I corect in that the generator doesn't generate the Unit classes in first\units. it just creates the files stored in generated?

[Gold856]

Yes. The pregen scripts write the generated files to src/generated/main for a given subproject.

[narmstro2020]

At this point I've added all of the linear and angular units for the feedforward constants (kv, ka).

I am not married to the names of these units and will rename them when prompted.
Always hard to name things in programming.

Also if it hasn't been said enough @SamCarlberg did a wonderful job on the rewrite.
It is so much nicer to use this API now.

[SamCarlberg]

@narmstro2020 What do you see this providing that Per<VoltageUnit, LinearVelocity> (and friends) do not?

[narmstro2020]

@narmstro2020 What do you see this providing that Per<VoltageUnit, LinearVelocity> (and friends) do not?

Really just ease of use from the student perspectice. I think the named units shouldn’t rely on the syntax of generics for the type whenever possible. Makes housing these in constants a bit easier to read.

That being said I’m open to modifications to the name

[SamCarlberg]

That's fair, though I'm personally ambivalent. A similar set of units for PID constants would also be useful in conjunction with these so users don't have a mix of generic Per<VoltageUnit, DistanceUnit> and sharp VoltagePerXYZ objects

[calcmogul]

Note that not all feedback controllers output voltage. The variety of unit possibilities is why PIDController is unitless.

[narmstro2020]

Note that not all feedback controllers output voltage. The variety of unit possibilities is why PIDController is unitless.

I thought about that which I why I left it out in this PR. I guess I could just make them for the common motor usages, but I will defer to the reviewers as to what would be best.

[narmstro2020]

I'll go ahead and add a PID set for motor control voltage/position and motor control voltage/velocity.

[narmstro2020]

@calcmogul @SamCarlberg

So I haven't added units for the common PID.
Should I or not bother. I'm okay either way, I just wanted a recommendation before proceeding.

[SamCarlberg]

@narmstro2020 I'm ambivalent, and we can always add them later

[narmstro2020]

@narmstro2020 I'm ambivalent, and we can always add them later

I will consider this PR done in regards to new features then. I'll make changes as requested of course.